IB Biology SL Flashcards: Complete Course Review

Review the current IB Biology Standard Level course with 960 independently written active-recall cards covering all 34 SL topics across molecules, cells, organisms, genetics, evolution, and ecology.

Về bộ thẻ này

Study the current IB Biology SL course with 960 independently written English flashcards. The deck covers all 34 Standard Level topics through four broad groups: molecules and cells; metabolism and genetics; organisms and systems; and evolution and ecology.

Cards move from essential terms and structures to functions, mechanisms, comparisons, predictions, and compact interpretation prompts. Useful two-way term cards are separated by at least three unrelated cards, while explanatory answers are kept in the direction that supports meaningful recall. Every card carries the root tag ib-bio-sl and exactly one broad group tag.

The order introduces prerequisite ideas before dependent ones and progresses from simpler recall to more demanding reasoning within each topic. The deck is designed for ongoing spaced review. It does not replace data-heavy practice papers, extended-response practice, laboratory work, or the scientific investigation.

Reviewed in 2026 against the current Biology Standard Level course, first assessed in 2025.

Independent, unofficial study aid based on common biological knowledge. Not affiliated with or endorsed by the International Baccalaureate Organization. No copied IB examination questions, mark schemes, or curriculum text are included.

Check the official IB Biology course page for authoritative requirements.

Thẻ trong bộ này

  1. Thẻ 1

    Câu hỏi

    What is water polarity?

    Câu trả lời

    The unequal sharing of electrons in a water molecule, giving oxygen a partial negative charge and the hydrogens partial positive charges.

  2. Thẻ 2

    Câu hỏi

    What is a hydrogen bond?

    Câu trả lời

    A weak attraction between a partially positive hydrogen atom and a partially negative atom in another molecule.

  3. Thẻ 3

    Câu hỏi

    What is cohesion?

    Câu trả lời

    Attraction between molecules of the same substance.

  4. Thẻ 4

    Câu hỏi

    What is adhesion?

    Câu trả lời

    Attraction between molecules of different substances.

  5. Thẻ 5

    Câu hỏi

    Which term describes unequal charge distribution within a water molecule?

    Câu trả lời

    water polarity

  6. Thẻ 6

    Câu hỏi

    Which term describes the intermolecular attraction that links neighboring water molecules?

    Câu trả lời

    a hydrogen bond

  7. Thẻ 7

    Câu hỏi

    Which term describes attraction between molecules of the same substance?

    Câu trả lời

    cohesion

  8. Thẻ 8

    Câu hỏi

    Which term describes attraction between water and a different material?

    Câu trả lời

    adhesion

  9. Thẻ 9

    Câu hỏi

    What is a solvent?

    Câu trả lời

    A liquid that dissolves solutes to form a solution.

  10. Thẻ 10

    Câu hỏi

    What is specific heat capacity?

    Câu trả lời

    The energy required to raise the temperature of a unit mass of a substance by one degree.

  11. Thẻ 11

    Câu hỏi

    What is latent heat of vaporization?

    Câu trả lời

    The energy required to vaporize a specified amount of liquid without changing its temperature.

  12. Thẻ 12

    Câu hỏi

    Why does ice float on liquid water?

    Câu trả lời

    Hydrogen bonds hold water molecules in an open lattice in ice, making ice less dense than liquid water.

  13. Thẻ 13

    Câu hỏi

    Which term describes a liquid that dissolves solutes?

    Câu trả lời

    a solvent

  14. Thẻ 14

    Câu hỏi

    Which term describes the energy needed to raise a unit mass by one degree?

    Câu trả lời

    specific heat capacity

  15. Thẻ 15

    Câu hỏi

    Which term describes the energy needed to vaporize a liquid without a temperature change?

    Câu trả lời

    latent heat of vaporization

  16. Thẻ 16

    Câu hỏi

    Which property of water makes sweating an effective cooling mechanism?

    Câu trả lời

    Water absorbs substantial energy as it evaporates; the highest-energy molecules leave, carrying heat away from the skin.

  17. Thẻ 17

    Câu hỏi

    Why does water resist rapid temperature change?

    Câu trả lời

    Many hydrogen bonds must absorb energy before molecular motion increases substantially, giving water a high specific heat capacity.

  18. Thẻ 18

    Câu hỏi

    How do cohesion and adhesion support water transport in narrow tubes?

    Câu trả lời

    Cohesion keeps water molecules connected, while adhesion helps the water column cling to the tube wall.

  19. Thẻ 19

    Câu hỏi

    How does water participate differently in hydrolysis and condensation?

    Câu trả lời

    Hydrolysis consumes water to split a bond; condensation forms a bond and releases water.

  20. Thẻ 20

    Câu hỏi

    How does floating ice protect aquatic life in winter?

    Câu trả lời

    Surface ice insulates the liquid water below, slowing further heat loss and preventing the whole body of water from freezing rapidly.

  21. Thẻ 21

    Câu hỏi

    Why is water effective for transporting many biological solutes?

    Câu trả lời

    Its polarity allows ions and other polar molecules to become surrounded and dispersed in solution.

  22. Thẻ 22

    Câu hỏi

    Why do nonpolar substances tend to cluster in water?

    Câu trả lời

    Clustering reduces the nonpolar surface exposed to water, allowing more water molecules to maintain hydrogen-bond interactions.

  23. Thẻ 23

    Câu hỏi

    What is a nucleotide?

    Câu trả lời

    A nucleic-acid monomer made of a pentose sugar, a phosphate group, and a nitrogenous base.

  24. Thẻ 24

    Câu hỏi

    What is a nucleoside?

    Câu trả lời

    A nitrogenous base joined to a pentose sugar, without a phosphate group.

  25. Thẻ 25

    Câu hỏi

    What is a phosphodiester bond?

    Câu trả lời

    A covalent bond linking the phosphate of one nucleotide to the sugar of the next nucleotide.

  26. Thẻ 26

    Câu hỏi

    What is DNA?

    Câu trả lời

    A usually double-stranded nucleic acid that stores hereditary information in its base sequence.

  27. Thẻ 27

    Câu hỏi

    Which term describes a sugar-phosphate-base monomer?

    Câu trả lời

    a nucleotide

  28. Thẻ 28

    Câu hỏi

    Which term describes a base joined to a sugar but no phosphate?

    Câu trả lời

    a nucleoside

  29. Thẻ 29

    Câu hỏi

    Which term describes the covalent linkage in a nucleic-acid sugar-phosphate backbone?

    Câu trả lời

    a phosphodiester bond

  30. Thẻ 30

    Câu hỏi

    Which term describes the nucleic acid that usually stores hereditary information?

    Câu trả lời

    DNA

  31. Thẻ 31

    Câu hỏi

    What is RNA?

    Câu trả lời

    A usually single-stranded nucleic acid involved in expressing and regulating genetic information.

  32. Thẻ 32

    Câu hỏi

    What are antiparallel DNA strands?

    Câu trả lời

    Two DNA strands that run in opposite 5′ to 3′ directions.

  33. Thẻ 33

    Câu hỏi

    What is complementary base pairing?

    Câu trả lời

    Specific pairing in which adenine pairs with thymine in DNA, or uracil in RNA, and cytosine pairs with guanine.

  34. Thẻ 34

    Câu hỏi

    What is a purine?

    Câu trả lời

    A nitrogenous base with two fused rings; adenine and guanine are purines.

  35. Thẻ 35

    Câu hỏi

    Which term describes the usually single-stranded nucleic acid used in gene expression?

    Câu trả lời

    RNA

  36. Thẻ 36

    Câu hỏi

    Which term describes DNA strands running in opposite directions?

    Câu trả lời

    antiparallel DNA strands

  37. Thẻ 37

    Câu hỏi

    Which term describes specific A–T or A–U and C–G pairing?

    Câu trả lời

    complementary base pairing

  38. Thẻ 38

    Câu hỏi

    Which term describes a two-ring nitrogenous base?

    Câu trả lời

    a purine

  39. Thẻ 39

    Câu hỏi

    What is a pyrimidine?

    Câu trả lời

    A nitrogenous base with one ring; cytosine, thymine, and uracil are pyrimidines.

  40. Thẻ 40

    Câu hỏi

    What is a genome?

    Câu trả lời

    The complete genetic material of an organism or cell.

  41. Thẻ 41

    Câu hỏi

    What three structural features commonly distinguish RNA from DNA?

    Câu trả lời

    RNA usually contains ribose, uses uracil instead of thymine, and is single-stranded rather than double-stranded.

  42. Thẻ 42

    Câu hỏi

    What determines the base sequence of the second DNA strand?

    Câu trả lời

    Complementary base-pairing rules determine it: A pairs with T, and C pairs with G.

  43. Thẻ 43

    Câu hỏi

    Which term describes a one-ring nitrogenous base?

    Câu trả lời

    a pyrimidine

  44. Thẻ 44

    Câu hỏi

    Which term describes the complete genetic material of an organism?

    Câu trả lời

    a genome

  45. Thẻ 45

    Câu hỏi

    What do the 5′ and 3′ labels of a nucleic-acid strand refer to?

    Câu trả lời

    They refer to numbered carbon atoms in the pentose sugar and define the strand's chemical direction.

  46. Thẻ 46

    Câu hỏi

    Where is genetic information encoded in DNA?

    Câu trả lời

    In the order of nitrogenous bases along the DNA strand.

  47. Thẻ 47

    Câu hỏi

    Why is ATP classified as a nucleotide?

    Câu trả lời

    It contains adenine, ribose, and phosphate groups, the three component types of a nucleotide.

  48. Thẻ 48

    Câu hỏi

    How do mRNA, tRNA, and rRNA contribute to protein synthesis?

    Câu trả lời

    mRNA carries the coding sequence, tRNA delivers amino acids, and rRNA forms the catalytic and structural core of ribosomes.

  49. Thẻ 49

    Câu hỏi

    How are a gene and a chromosome related?

    Câu trả lời

    A gene is a DNA sequence with a biological function; a chromosome is one long DNA molecule containing many genes and other sequences.

  50. Thẻ 50

    Câu hỏi

    What happens to double-stranded DNA when it is denatured by heat?

    Câu trả lời

    Hydrogen bonds between complementary bases break and the two strands separate; the covalent backbones usually remain intact.

  51. Thẻ 51

    Câu hỏi

    Why can each DNA strand serve as a template during replication?

    Câu trả lời

    Its base sequence determines a complementary sequence through specific base pairing.

  52. Thẻ 52

    Câu hỏi

    In which direction are new nucleic-acid strands synthesized?

    Câu trả lời

    Nucleotides are added to the 3′ end, so synthesis proceeds 5′ to 3′.

  53. Thẻ 53

    Câu hỏi

    What is a monosaccharide?

    Câu trả lời

    A single sugar unit that can serve as a carbohydrate monomer.

  54. Thẻ 54

    Câu hỏi

    What is a disaccharide?

    Câu trả lời

    A carbohydrate formed from two monosaccharides joined by a glycosidic bond.

  55. Thẻ 55

    Câu hỏi

    What is a polysaccharide?

    Câu trả lời

    A polymer made from many monosaccharide units.

  56. Thẻ 56

    Câu hỏi

    What is a glycosidic bond?

    Câu trả lời

    A covalent bond joining monosaccharides in a carbohydrate.

  57. Thẻ 57

    Câu hỏi

    Which term describes a single sugar unit?

    Câu trả lời

    a monosaccharide

  58. Thẻ 58

    Câu hỏi

    Which term describes two monosaccharides joined together?

    Câu trả lời

    a disaccharide

  59. Thẻ 59

    Câu hỏi

    Which term describes a polymer of many sugar units?

    Câu trả lời

    a polysaccharide

  60. Thẻ 60

    Câu hỏi

    Which term describes the covalent linkage between monosaccharides?

    Câu trả lời

    a glycosidic bond

  61. Thẻ 61

    Câu hỏi

    What is a triglyceride?

    Câu trả lời

    A lipid formed from glycerol joined to three fatty acids.

  62. Thẻ 62

    Câu hỏi

    What is a fatty acid?

    Câu trả lời

    A hydrocarbon chain with a carboxyl group that can form part of many lipids.

  63. Thẻ 63

    Câu hỏi

    What is a saturated fatty acid?

    Câu trả lời

    A fatty acid with no carbon-carbon double bonds in its hydrocarbon chain.

  64. Thẻ 64

    Câu hỏi

    What is a phospholipid?

    Câu trả lời

    An amphipathic lipid with a phosphate-containing hydrophilic head and hydrophobic fatty-acid tails.

  65. Thẻ 65

    Câu hỏi

    Which term describes glycerol joined to three fatty acids?

    Câu trả lời

    a triglyceride

  66. Thẻ 66

    Câu hỏi

    Which term describes a hydrocarbon chain ending in a carboxyl group?

    Câu trả lời

    a fatty acid

  67. Thẻ 67

    Câu hỏi

    Which term describes a fatty acid without carbon-carbon double bonds?

    Câu trả lời

    a saturated fatty acid

  68. Thẻ 68

    Câu hỏi

    Which term describes a lipid with a polar head and nonpolar tails?

    Câu trả lời

    a phospholipid

  69. Thẻ 69

    Câu hỏi

    How is a glycosidic bond formed between two monosaccharides?

    Câu trả lời

    A condensation reaction joins them and releases a molecule of water.

  70. Thẻ 70

    Câu hỏi

    How is a polysaccharide broken into smaller sugars?

    Câu trả lời

    Hydrolysis adds water across glycosidic bonds, splitting the polymer.

  71. Thẻ 71

    Câu hỏi

    Which polysaccharides store glucose in plants and animals?

    Câu trả lời

    Starch stores glucose in plants; glycogen stores glucose in animals and fungi.

  72. Thẻ 72

    Câu hỏi

    Why is cellulose suitable for plant cell walls?

    Câu trả lời

    Its straight β-glucose chains hydrogen-bond into strong microfibrils that resist stretching.

  73. Thẻ 73

    Câu hỏi

    Why do lipids store more energy per gram than carbohydrates?

    Câu trả lời

    Lipids contain more energy-rich carbon-hydrogen bonds and are more reduced.

  74. Thẻ 74

    Câu hỏi

    Why do phospholipids form bilayers in water?

    Câu trả lời

    Hydrophilic heads interact with water while hydrophobic tails cluster away from water.

  75. Thẻ 75

    Câu hỏi

    Besides energy storage, what are three biological roles of lipids?

    Câu trả lời

    They form membranes, provide thermal insulation and cushioning, and can act as signaling molecules.

  76. Thẻ 76

    Câu hỏi

    How do cis double bonds affect fatty-acid packing and melting point?

    Câu trả lời

    They introduce bends that reduce close packing, usually lowering the melting point.

  77. Thẻ 77

    Câu hỏi

    What is an amino acid?

    Câu trả lời

    A protein monomer with an amino group, a carboxyl group, a hydrogen, and a variable R group attached to a central carbon.

  78. Thẻ 78

    Câu hỏi

    What is a peptide bond?

    Câu trả lời

    The covalent bond formed between the amino group of one amino acid and the carboxyl group of another.

  79. Thẻ 79

    Câu hỏi

    What is a polypeptide?

    Câu trả lời

    A chain of amino acids joined by peptide bonds.

  80. Thẻ 80

    Câu hỏi

    What is protein primary structure?

    Câu trả lời

    The amino-acid sequence of a polypeptide.

  81. Thẻ 81

    Câu hỏi

    Which term describes a protein monomer with amino, carboxyl, and variable R groups?

    Câu trả lời

    an amino acid

  82. Thẻ 82

    Câu hỏi

    Which term describes the covalent linkage between amino acids?

    Câu trả lời

    a peptide bond

  83. Thẻ 83

    Câu hỏi

    Which term describes a chain of peptide-linked amino acids?

    Câu trả lời

    a polypeptide

  84. Thẻ 84

    Câu hỏi

    Which term describes a protein's amino-acid sequence?

    Câu trả lời

    protein primary structure

  85. Thẻ 85

    Câu hỏi

    What is protein secondary structure?

    Câu trả lời

    Local folding such as α-helices and β-sheets stabilized mainly by backbone hydrogen bonds.

  86. Thẻ 86

    Câu hỏi

    What is protein tertiary structure?

    Câu trả lời

    The overall three-dimensional shape of one polypeptide produced by interactions among R groups and the backbone.

  87. Thẻ 87

    Câu hỏi

    What is protein quaternary structure?

    Câu trả lời

    The arrangement of multiple polypeptide subunits in one functional protein.

  88. Thẻ 88

    Câu hỏi

    What is protein denaturation?

    Câu trả lời

    Loss of a protein's normal three-dimensional shape and therefore usually its function.

  89. Thẻ 89

    Câu hỏi

    Which term describes local α-helix and β-sheet folding?

    Câu trả lời

    protein secondary structure

  90. Thẻ 90

    Câu hỏi

    Which term describes the overall three-dimensional shape of one polypeptide?

    Câu trả lời

    protein tertiary structure

  91. Thẻ 91

    Câu hỏi

    Which term describes the association of multiple polypeptide subunits?

    Câu trả lời

    protein quaternary structure

  92. Thẻ 92

    Câu hỏi

    Which term describes loss of a protein's native shape?

    Câu trả lời

    protein denaturation

  93. Thẻ 93

    Câu hỏi

    What mainly gives different amino acids their different chemical properties?

    Câu trả lời

    Their variable R groups.

  94. Thẻ 94

    Câu hỏi

    What reaction forms a peptide bond?

    Câu trả lời

    A condensation reaction releases water as the amino and carboxyl groups join.

  95. Thẻ 95

    Câu hỏi

    Why can high temperature denature a protein?

    Câu trả lời

    Increased molecular motion disrupts weak interactions that maintain the protein's shape.

  96. Thẻ 96

    Câu hỏi

    Why can extreme pH denature a protein?

    Câu trả lời

    It changes the charges of R groups and disrupts ionic and hydrogen-bond interactions.

  97. Thẻ 97

    Câu hỏi

    How do fibrous and globular proteins generally differ?

    Câu trả lời

    Fibrous proteins are elongated and mainly structural; globular proteins are compact and often perform dynamic functions.

  98. Thẻ 98

    Câu hỏi

    Why is three-dimensional shape crucial to protein function?

    Câu trả lời

    It creates specific binding, catalytic, structural, or interaction surfaces.

  99. Thẻ 99

    Câu hỏi

    Name four broad biological roles of proteins.

    Câu trả lời

    Catalysis, transport, signaling, defense, movement, and structural support are major roles; any four are sufficient.

  100. Thẻ 100

    Câu hỏi

    How can changing one amino acid alter protein function?

    Câu trả lời

    The substitution can change R-group interactions, folding, stability, or an active or binding site.

  101. Thẻ 101

    Câu hỏi

    What is cell theory?

    Câu trả lời

    The principles that living organisms are made of cells, cells are the basic units of life, and cells arise from pre-existing cells.

  102. Thẻ 102

    Câu hỏi

    What is a prokaryotic cell?

    Câu trả lời

    A cell without a nucleus or other membrane-bound organelles.

  103. Thẻ 103

    Câu hỏi

    What is a eukaryotic cell?

    Câu trả lời

    A cell with DNA enclosed in a nucleus and with membrane-bound organelles.

  104. Thẻ 104

    Câu hỏi

    What is the nucleus?

    Câu trả lời

    The double-membrane organelle that contains most of a eukaryotic cell's DNA.

  105. Thẻ 105

    Câu hỏi

    Which term describes the principles describing cells as life's basic units?

    Câu trả lời

    cell theory

  106. Thẻ 106

    Câu hỏi

    Which term describes a cell lacking a nucleus and membrane-bound organelles?

    Câu trả lời

    a prokaryotic cell

  107. Thẻ 107

    Câu hỏi

    Which term describes a cell with a nucleus and membrane-bound organelles?

    Câu trả lời

    a eukaryotic cell

  108. Thẻ 108

    Câu hỏi

    Which term describes the organelle containing most eukaryotic DNA?

    Câu trả lời

    the nucleus

  109. Thẻ 109

    Câu hỏi

    What is a ribosome?

    Câu trả lời

    A molecular complex of rRNA and proteins that synthesizes polypeptides.

  110. Thẻ 110

    Câu hỏi

    What is the cytoplasm?

    Câu trả lời

    The material inside the plasma membrane but outside the nucleus, including cytosol and organelles.

  111. Thẻ 111

    Câu hỏi

    What is the plasma membrane?

    Câu trả lời

    The selectively permeable boundary separating a cell from its environment.

  112. Thẻ 112

    Câu hỏi

    What is a cell wall?

    Câu trả lời

    A rigid extracellular layer that supports and protects cells in plants, fungi, and most prokaryotes.

  113. Thẻ 113

    Câu hỏi

    Which term describes the complex that synthesizes polypeptides?

    Câu trả lời

    a ribosome

  114. Thẻ 114

    Câu hỏi

    Which term describes cell contents inside the plasma membrane but outside the nucleus?

    Câu trả lời

    the cytoplasm

  115. Thẻ 115

    Câu hỏi

    Which term describes the selectively permeable cell boundary?

    Câu trả lời

    the plasma membrane

  116. Thẻ 116

    Câu hỏi

    Which term describes a rigid extracellular support layer?

    Câu trả lời

    a cell wall

  117. Thẻ 117

    Câu hỏi

    What is the nucleoid?

    Câu trả lời

    The non-membrane-bound region containing the main chromosome of a prokaryotic cell.

  118. Thẻ 118

    Câu hỏi

    What is the cytoskeleton?

    Câu trả lời

    A dynamic network of protein filaments involved in cell shape, transport, division, and movement.

  119. Thẻ 119

    Câu hỏi

    What structures are shared by all cells?

    Câu trả lời

    A plasma membrane, cytoplasm, genetic material, and ribosomes.

  120. Thẻ 120

    Câu hỏi

    Which structures distinguish a typical plant cell from a typical animal cell?

    Câu trả lời

    A plant cell has a cellulose wall, chloroplasts in photosynthetic tissues, and a large central vacuole; an animal cell lacks these.

  121. Thẻ 121

    Câu hỏi

    Which term describes the prokaryotic chromosome-containing region?

    Câu trả lời

    the nucleoid

  122. Thẻ 122

    Câu hỏi

    Which term describes the internal network of protein filaments?

    Câu trả lời

    the cytoskeleton

  123. Thẻ 123

    Câu hỏi

    How is genetic material commonly organized in a prokaryotic cell?

    Câu trả lời

    The main DNA is usually one circular chromosome in the nucleoid, often accompanied by smaller plasmids.

  124. Thẻ 124

    Câu hỏi

    How is microscope magnification calculated?

    Câu trả lời

    Magnification = image size ÷ actual size, using the same units.

  125. Thẻ 125

    Câu hỏi

    What does microscope resolution describe?

    Câu trả lời

    The ability to distinguish two close points as separate.

  126. Thẻ 126

    Câu hỏi

    Arrange these from smallest to largest: ribosome, bacterium, animal cell.

    Câu trả lời

    Ribosome, bacterium, animal cell.

  127. Thẻ 127

    Câu hỏi

    How does the cytoskeleton support intracellular transport?

    Câu trả lời

    Motor proteins move vesicles and other cargo along cytoskeletal filaments.

  128. Thẻ 128

    Câu hỏi

    Why does a small cell usually exchange materials more efficiently than a geometrically similar large cell?

    Câu trả lời

    It has a larger surface-area-to-volume ratio, providing more exchange surface per unit of cell contents.

  129. Thẻ 129

    Câu hỏi

    Why is a cell more than a collection of isolated molecules?

    Câu trả lời

    Organized interactions among components produce emergent functions such as metabolism, regulation, and reproduction.

  130. Thẻ 130

    Câu hỏi

    What major advantage do membrane-bound organelles give eukaryotic cells?

    Câu trả lời

    They separate incompatible reactions and create specialized local conditions.

  131. Thẻ 131

    Câu hỏi

    What is a phospholipid bilayer?

    Câu trả lời

    A double layer of phospholipids with hydrophilic heads facing water and hydrophobic tails facing inward.

  132. Thẻ 132

    Câu hỏi

    What is the fluid mosaic model?

    Câu trả lời

    A model describing membranes as mobile phospholipids containing a changing mosaic of proteins and other components.

  133. Thẻ 133

    Câu hỏi

    What is an integral membrane protein?

    Câu trả lời

    A protein embedded in the bilayer, often spanning it.

  134. Thẻ 134

    Câu hỏi

    What is a peripheral membrane protein?

    Câu trả lời

    A protein attached to a membrane surface rather than embedded in the bilayer.

  135. Thẻ 135

    Câu hỏi

    Which term describes a double phospholipid layer with inward-facing tails?

    Câu trả lời

    a phospholipid bilayer

  136. Thẻ 136

    Câu hỏi

    Which term describes the model of a mobile lipid layer containing varied proteins?

    Câu trả lời

    the fluid mosaic model

  137. Thẻ 137

    Câu hỏi

    Which term describes a protein embedded within the lipid bilayer?

    Câu trả lời

    an integral membrane protein

  138. Thẻ 138

    Câu hỏi

    Which term describes a protein attached to a membrane surface?

    Câu trả lời

    a peripheral membrane protein

  139. Thẻ 139

    Câu hỏi

    What is membrane cholesterol?

    Câu trả lời

    An amphipathic lipid that buffers membrane fluidity and reduces permeability in animal cells.

  140. Thẻ 140

    Câu hỏi

    What is a glycoprotein?

    Câu trả lời

    A protein with an attached carbohydrate chain, often used in recognition, adhesion, or signaling.

  141. Thẻ 141

    Câu hỏi

    What is diffusion?

    Câu trả lời

    Net movement of particles from a region of higher concentration to lower concentration due to random motion.

  142. Thẻ 142

    Câu hỏi

    What is osmosis?

    Câu trả lời

    Net movement of water across a selectively permeable membrane from higher water potential to lower water potential.

  143. Thẻ 143

    Câu hỏi

    Which term describes the animal-membrane lipid that buffers fluidity?

    Câu trả lời

    membrane cholesterol

  144. Thẻ 144

    Câu hỏi

    Which term describes a carbohydrate-bearing protein?

    Câu trả lời

    a glycoprotein

  145. Thẻ 145

    Câu hỏi

    Which term describes net movement down a concentration gradient?

    Câu trả lời

    diffusion

  146. Thẻ 146

    Câu hỏi

    Which term describes net water movement across a selectively permeable membrane?

    Câu trả lời

    osmosis

  147. Thẻ 147

    Câu hỏi

    What is facilitated diffusion?

    Câu trả lời

    Passive movement down a gradient through a membrane channel or carrier protein.

  148. Thẻ 148

    Câu hỏi

    What is active transport?

    Câu trả lời

    Energy-requiring movement of a substance against its concentration or electrochemical gradient.

  149. Thẻ 149

    Câu hỏi

    Why is the phospholipid bilayer selectively permeable?

    Câu trả lời

    Its hydrophobic interior allows small nonpolar molecules through more readily than ions and most large or polar molecules.

  150. Thẻ 150

    Câu hỏi

    How do simple diffusion and facilitated diffusion differ?

    Câu trả lời

    Both are passive, but facilitated diffusion uses specific membrane proteins while simple diffusion passes through the bilayer.

  151. Thẻ 151

    Câu hỏi

    Which term describes passive transport through a channel or carrier?

    Câu trả lời

    facilitated diffusion

  152. Thẻ 152

    Câu hỏi

    Which term describes energy-dependent transport against a gradient?

    Câu trả lời

    active transport

  153. Thẻ 153

    Câu hỏi

    How do channel and carrier proteins differ?

    Câu trả lời

    Channels provide hydrophilic pores; carriers bind solutes and change shape to move them.

  154. Thẻ 154

    Câu hỏi

    How can an ATP-driven pump maintain an ion gradient?

    Câu trả lời

    It couples ATP hydrolysis to a conformational change that moves ions against their electrochemical gradient.

  155. Thẻ 155

    Câu hỏi

    How does endocytosis move material into a cell?

    Câu trả lời

    The plasma membrane folds inward and pinches off a vesicle containing the material.

  156. Thẻ 156

    Câu hỏi

    How does exocytosis move material out of a cell?

    Câu trả lời

    An intracellular vesicle fuses with the plasma membrane and releases its contents outside.

  157. Thẻ 157

    Câu hỏi

    What happens to an animal cell in a strongly hypotonic solution?

    Câu trả lời

    Water enters by osmosis; without a cell wall, the cell may swell and lyse.

  158. Thẻ 158

    Câu hỏi

    Does molecular movement stop when diffusion reaches equilibrium?

    Câu trả lời

    No. Molecules continue moving randomly, but there is no net movement between regions.

  159. Thẻ 159

    Câu hỏi

    How does decreasing temperature generally affect membrane fluidity?

    Câu trả lời

    It reduces phospholipid movement and makes the membrane less fluid.

  160. Thẻ 160

    Câu hỏi

    Why do unsaturated fatty-acid tails increase membrane fluidity?

    Câu trả lời

    Their cis double-bond bends prevent phospholipids from packing tightly.

  161. Thẻ 161

    Câu hỏi

    What changes increase the rate of simple diffusion across a membrane?

    Câu trả lời

    A steeper gradient, larger surface area, higher temperature, shorter distance, and greater membrane permeability increase the rate.

  162. Thẻ 162

    Câu hỏi

    What is a mitochondrion?

    Câu trả lời

    A double-membrane organelle where most aerobic ATP production occurs.

  163. Thẻ 163

    Câu hỏi

    What is a chloroplast?

    Câu trả lời

    A double-membrane organelle where photosynthesis occurs in plants and algae.

  164. Thẻ 164

    Câu hỏi

    What is rough endoplasmic reticulum?

    Câu trả lời

    A membrane network bearing ribosomes that synthesizes and begins processing many secreted and membrane proteins.

  165. Thẻ 165

    Câu hỏi

    What is smooth endoplasmic reticulum?

    Câu trả lời

    A membrane network involved in lipid synthesis, detoxification, and calcium storage.

  166. Thẻ 166

    Câu hỏi

    Which term describes the main organelle of aerobic ATP production?

    Câu trả lời

    a mitochondrion

  167. Thẻ 167

    Câu hỏi

    Which term describes the photosynthetic organelle of plants and algae?

    Câu trả lời

    a chloroplast

  168. Thẻ 168

    Câu hỏi

    Which term describes the ribosome-studded membrane network?

    Câu trả lời

    rough endoplasmic reticulum

  169. Thẻ 169

    Câu hỏi

    Which term describes the membrane network that lacks ribosomes and synthesizes lipids?

    Câu trả lời

    smooth endoplasmic reticulum

  170. Thẻ 170

    Câu hỏi

    What is the Golgi apparatus?

    Câu trả lời

    Stacked membranes that modify, sort, and package proteins and lipids into vesicles.

  171. Thẻ 171

    Câu hỏi

    What is a lysosome?

    Câu trả lời

    An acidic enzyme-containing organelle that digests macromolecules and worn cellular components.

  172. Thẻ 172

    Câu hỏi

    What is a vesicle?

    Câu trả lời

    A small membrane-bound compartment used for transport, storage, or chemical reactions.

  173. Thẻ 173

    Câu hỏi

    What is the central vacuole?

    Câu trả lời

    A large plant-cell compartment that stores solutes and helps maintain turgor pressure.

  174. Thẻ 174

    Câu hỏi

    Which term describes the organelle that modifies and sorts cellular cargo?

    Câu trả lời

    the Golgi apparatus

  175. Thẻ 175

    Câu hỏi

    Which term describes the acidic digestive organelle?

    Câu trả lời

    a lysosome

  176. Thẻ 176

    Câu hỏi

    Which term describes a small membrane-bound transport compartment?

    Câu trả lời

    a vesicle

  177. Thẻ 177

    Câu hỏi

    Which term describes the large plant compartment that supports turgor?

    Câu trả lời

    the central vacuole

  178. Thẻ 178

    Câu hỏi

    Why can compartmentalization increase metabolic efficiency?

    Câu trả lời

    It concentrates enzymes and substrates, maintains suitable local conditions, and separates incompatible reactions.

  179. Thẻ 179

    Câu hỏi

    How do mitochondrial cristae support ATP production?

    Câu trả lời

    They increase inner-membrane area for electron transport chains and ATP synthase.

  180. Thẻ 180

    Câu hỏi

    Why are chloroplast thylakoids arranged as extensive membranes?

    Câu trả lời

    They provide a large surface for light-absorbing complexes, electron transport chains, and ATP synthase.

  181. Thẻ 181

    Câu hỏi

    What is the main function of the nucleolus?

    Câu trả lời

    It produces rRNA and assembles ribosomal subunits.

  182. Thẻ 182

    Câu hỏi

    Trace a secreted protein from synthesis to release.

    Câu trả lời

    Ribosome on rough ER → ER lumen → transport vesicle → Golgi apparatus → secretory vesicle → plasma membrane → exocytosis.

  183. Thẻ 183

    Câu hỏi

    Why does a lysosome maintain an acidic interior?

    Câu trả lời

    Its hydrolytic enzymes work best at low pH, and acidity helps confine their activity from the cytosol.

  184. Thẻ 184

    Câu hỏi

    How do the nucleus, ribosomes, ER, and Golgi cooperate in protein production?

    Câu trả lời

    DNA instructions are transcribed in the nucleus; ribosomes translate them; ER folds or modifies many products; Golgi further modifies and sorts them.

  185. Thẻ 185

    Câu hỏi

    How are transport vesicles directed to the correct target membrane?

    Câu trả lời

    Specific recognition proteins on vesicles and target membranes interact, allowing selective docking and fusion.

  186. Thẻ 186

    Câu hỏi

    What is cell differentiation?

    Câu trả lời

    The process by which a cell develops specialized structure and function.

  187. Thẻ 187

    Câu hỏi

    What is a stem cell?

    Câu trả lời

    An unspecialized cell able to self-renew and produce differentiated cells.

  188. Thẻ 188

    Câu hỏi

    What is gene expression?

    Câu trả lời

    Use of genetic information to produce a functional RNA or protein product.

  189. Thẻ 189

    Câu hỏi

    What is a tissue?

    Câu trả lời

    A coordinated group of similar or related cells performing a shared function.

  190. Thẻ 190

    Câu hỏi

    Which term describes development of specialized cell structure and function?

    Câu trả lời

    cell differentiation

  191. Thẻ 191

    Câu hỏi

    Which term describes an unspecialized self-renewing cell?

    Câu trả lời

    a stem cell

  192. Thẻ 192

    Câu hỏi

    Which term describes production of a functional product from genetic information?

    Câu trả lời

    gene expression

  193. Thẻ 193

    Câu hỏi

    Which term describes a group of coordinated cells with a shared function?

    Câu trả lời

    a tissue

  194. Thẻ 194

    Câu hỏi

    What is an organ?

    Câu trả lời

    A structure made of multiple tissues working together for particular functions.

  195. Thẻ 195

    Câu hỏi

    What is the organ-system level of biological organization?

    Câu trả lời

    A group of organs that coordinate to perform major functions for an organism.

  196. Thẻ 196

    Câu hỏi

    What is surface-area-to-volume ratio?

    Câu trả lời

    The amount of surface area available relative to the volume it must serve.

  197. Thẻ 197

    Câu hỏi

    How can two specialized cells have the same genome but different structures?

    Câu trả lời

    They express different sets and amounts of genes, producing different proteins and cellular features.

  198. Thẻ 198

    Câu hỏi

    Which term describes a structure composed of multiple tissue types?

    Câu trả lời

    an organ

  199. Thẻ 199

    Câu hỏi

    Which term describes the level of biological organization formed by coordinated organs?

    Câu trả lời

    an organ system

  200. Thẻ 200

    Câu hỏi

    Which term describes surface area available per unit volume?

    Câu trả lời

    surface-area-to-volume ratio

  201. Thẻ 201

    Câu hỏi

    How is a mammalian red blood cell specialized for oxygen transport?

    Câu trả lời

    Its biconcave shape increases exchange area, it is flexible, and loss of its nucleus leaves more space for hemoglobin.

  202. Thẻ 202

    Câu hỏi

    How is a sperm cell specialized for fertilization?

    Câu trả lời

    It has a flagellum for movement, many mitochondria for ATP, a haploid nucleus, and an acrosome containing enzymes.

  203. Thẻ 203

    Câu hỏi

    How is a neuron specialized for rapid communication?

    Câu trả lời

    Long processes carry signals over distance, branching dendrites receive inputs, and synaptic terminals transmit signals to other cells.

  204. Thẻ 204

    Câu hỏi

    How is a root hair cell specialized for mineral and water uptake?

    Câu trả lời

    Its long projection increases surface area, its thin wall shortens the pathway, and membrane transport proteins take up ions.

  205. Thẻ 205

    Câu hỏi

    How is a palisade mesophyll cell specialized for photosynthesis?

    Câu trả lời

    It contains many chloroplasts and is positioned near the upper leaf surface where light is strongest.

  206. Thẻ 206

    Câu hỏi

    How do ciliated epithelial cells help protect airways?

    Câu trả lời

    Their cilia move mucus containing trapped particles and microbes toward the throat.

  207. Thẻ 207

    Câu hỏi

    Why can extreme specialization reduce a cell's independence?

    Câu trả lời

    Resources and structures are committed to a narrow role, so the cell depends on other cells for functions it no longer performs well.

  208. Thẻ 208

    Câu hỏi

    What is water potential?

    Câu trả lời

    The potential energy of water per unit volume relative to pure water, used to predict the direction of water movement.

  209. Thẻ 209

    Câu hỏi

    What is solute potential?

    Câu trả lời

    The negative contribution of dissolved solutes to water potential.

  210. Thẻ 210

    Câu hỏi

    What is pressure potential?

    Câu trả lời

    The contribution of physical pressure to water potential.

  211. Thẻ 211

    Câu hỏi

    What is turgor pressure?

    Câu trả lời

    Outward pressure of a plant-cell interior against its cell wall after water uptake.

  212. Thẻ 212

    Câu hỏi

    Which term describes the tendency of water to move relative to pure water?

    Câu trả lời

    water potential

  213. Thẻ 213

    Câu hỏi

    Which term describes the water-potential component lowered by dissolved solutes?

    Câu trả lời

    solute potential

  214. Thẻ 214

    Câu hỏi

    Which term describes the water-potential component caused by physical pressure?

    Câu trả lời

    pressure potential

  215. Thẻ 215

    Câu hỏi

    Which term describes pressure of plant-cell contents against the wall?

    Câu trả lời

    turgor pressure

  216. Thẻ 216

    Câu hỏi

    What is plasmolysis?

    Câu trả lời

    Separation of the plasma membrane from the cell wall after a plant cell loses water.

  217. Thẻ 217

    Câu hỏi

    What is a flaccid plant cell?

    Câu trả lời

    A plant cell with insufficient turgor pressure to be firm.

  218. Thẻ 218

    Câu hỏi

    What is an isotonic condition?

    Câu trả lời

    A condition in which two solutions have equal effective water potential and no net water movement occurs.

  219. Thẻ 219

    Câu hỏi

    In which direction does water move across a permeable membrane?

    Câu trả lời

    From higher water potential to lower water potential.

  220. Thẻ 220

    Câu hỏi

    Which term describes membrane separation from the plant cell wall after water loss?

    Câu trả lời

    plasmolysis

  221. Thẻ 221

    Câu hỏi

    Which term describes a plant cell lacking firm turgor?

    Câu trả lời

    a flaccid plant cell

  222. Thẻ 222

    Câu hỏi

    Which term describes equal effective water potential across a membrane?

    Câu trả lời

    an isotonic condition

  223. Thẻ 223

    Câu hỏi

    What is the water potential of pure water at standard pressure?

    Câu trả lời

    Zero; adding solute makes water potential more negative.

  224. Thẻ 224

    Câu hỏi

    How are water potential, solute potential, and pressure potential related?

    Câu trả lời

    Water potential equals solute potential plus pressure potential: Ψ = Ψs + Ψp.

  225. Thẻ 225

    Câu hỏi

    Why does a plant cell usually become turgid rather than burst in a hypotonic solution?

    Câu trả lời

    Water entry raises pressure potential, while the rigid cell wall resists further expansion.

  226. Thẻ 226

    Câu hỏi

    What happens to a plant cell placed in a solution with much lower water potential?

    Câu trả lời

    Water leaves the cell, turgor falls, and severe loss can cause plasmolysis.

  227. Thẻ 227

    Câu hỏi

    Can two solutions have different solute concentrations but equal water potential?

    Câu trả lời

    Yes. A difference in pressure potential can offset a difference in solute potential.

  228. Thẻ 228

    Câu hỏi

    What is an enzyme?

    Câu trả lời

    A biological catalyst that increases reaction rate without being consumed.

  229. Thẻ 229

    Câu hỏi

    What is an active site?

    Câu trả lời

    The region of an enzyme where substrate binds and catalysis occurs.

  230. Thẻ 230

    Câu hỏi

    What is a substrate?

    Câu trả lời

    A reactant molecule on which an enzyme acts.

  231. Thẻ 231

    Câu hỏi

    What is activation energy?

    Câu trả lời

    The minimum energy input needed for a reaction to begin.

  232. Thẻ 232

    Câu hỏi

    Which term describes a biological catalyst?

    Câu trả lời

    an enzyme

  233. Thẻ 233

    Câu hỏi

    Which term describes the substrate-binding catalytic region of an enzyme?

    Câu trả lời

    an active site

  234. Thẻ 234

    Câu hỏi

    Which term describes a reactant bound and changed by an enzyme?

    Câu trả lời

    a substrate

  235. Thẻ 235

    Câu hỏi

    Which term describes the energy barrier that must be overcome for a reaction?

    Câu trả lời

    activation energy

  236. Thẻ 236

    Câu hỏi

    What is the induced-fit model?

    Câu trả lời

    The model in which substrate binding changes active-site shape to improve catalytic interactions.

  237. Thẻ 237

    Câu hỏi

    What is enzyme denaturation?

    Câu trả lời

    Loss of the active three-dimensional shape of an enzyme, usually causing loss of activity.

  238. Thẻ 238

    Câu hỏi

    What is competitive inhibition?

    Câu trả lời

    Inhibition caused by a molecule competing with substrate for the active site.

  239. Thẻ 239

    Câu hỏi

    What is noncompetitive inhibition?

    Câu trả lời

    Inhibition caused by binding away from the active site and reducing catalytic function.

  240. Thẻ 240

    Câu hỏi

    Which term describes the model where substrate binding reshapes the active site?

    Câu trả lời

    the induced-fit model

  241. Thẻ 241

    Câu hỏi

    Which term describes loss of an enzyme's functional shape?

    Câu trả lời

    enzyme denaturation

  242. Thẻ 242

    Câu hỏi

    Which term describes inhibition by active-site competition?

    Câu trả lời

    competitive inhibition

  243. Thẻ 243

    Câu hỏi

    Which term describes inhibition by binding outside the active site?

    Câu trả lời

    noncompetitive inhibition

  244. Thẻ 244

    Câu hỏi

    What is an enzyme optimum?

    Câu trả lời

    The condition, such as temperature or pH, at which an enzyme's activity is highest.

  245. Thẻ 245

    Câu hỏi

    What is feedback inhibition?

    Câu trả lời

    Control in which a pathway product inhibits an enzyme acting earlier in the pathway.

  246. Thẻ 246

    Câu hỏi

    How does an enzyme increase reaction rate?

    Câu trả lời

    It stabilizes the transition state and provides a pathway with lower activation energy.

  247. Thẻ 247

    Câu hỏi

    Why does enzyme activity often rise and then fall as temperature increases?

    Câu trả lời

    Molecular collisions initially increase, but excessive heat disrupts enzyme shape and denatures the active site.

  248. Thẻ 248

    Câu hỏi

    Which term describes the condition producing maximum enzyme activity?

    Câu trả lời

    an enzyme optimum

  249. Thẻ 249

    Câu hỏi

    Which term describes pathway control by inhibition from an end product?

    Câu trả lời

    feedback inhibition

  250. Thẻ 250

    Câu hỏi

    Why does each enzyme have a characteristic pH range?

    Câu trả lời

    pH changes the ionization of amino-acid side chains, affecting active-site shape and chemical interactions.

  251. Thẻ 251

    Câu hỏi

    Why does increasing substrate concentration eventually stop increasing enzyme rate?

    Câu trả lời

    At saturation, nearly all active sites are occupied and enzyme concentration limits the maximum rate.

  252. Thẻ 252

    Câu hỏi

    How does increasing enzyme concentration affect rate when substrate is abundant?

    Câu trả lời

    More active sites are available, so the initial rate increases roughly in proportion to enzyme concentration.

  253. Thẻ 253

    Câu hỏi

    What gives an enzyme substrate specificity?

    Câu trả lời

    The active site's shape, charge, polarity, and chemical groups complement particular substrates and transition states.

  254. Thẻ 254

    Câu hỏi

    What is one practical advantage of immobilizing an enzyme?

    Câu trả lời

    The enzyme can be separated from products and reused while conditions around it are controlled.

  255. Thẻ 255

    Câu hỏi

    Does an enzyme change a reaction's equilibrium position?

    Câu trả lời

    No. It speeds forward and reverse reactions but does not change the equilibrium constant or final equilibrium position.

  256. Thẻ 256

    Câu hỏi

    How can high substrate concentration reduce competitive inhibition?

    Câu trả lời

    More substrate molecules increase the chance that substrate rather than inhibitor occupies the active site.

  257. Thẻ 257

    Câu hỏi

    Why are metabolic reactions commonly organized into pathways?

    Câu trả lời

    A sequence of enzyme-controlled steps allows energy changes and intermediates to be controlled and coupled.

  258. Thẻ 258

    Câu hỏi

    What is ATP?

    Câu trả lời

    A nucleotide that transfers usable energy through coupling of its hydrolysis to cellular processes.

  259. Thẻ 259

    Câu hỏi

    What is cellular respiration?

    Câu trả lời

    Controlled release of energy from organic molecules to produce ATP.

  260. Thẻ 260

    Câu hỏi

    What is glycolysis?

    Câu trả lời

    A cytosolic pathway that splits glucose into two pyruvate molecules and yields a small amount of ATP and reduced electron carriers.

  261. Thẻ 261

    Câu hỏi

    What is pyruvate?

    Câu trả lời

    The three-carbon product of glycolysis that can enter aerobic or anaerobic pathways.

  262. Thẻ 262

    Câu hỏi

    Which term describes the cell's immediate phosphoryl-group energy carrier?

    Câu trả lời

    ATP

  263. Thẻ 263

    Câu hỏi

    Which term describes controlled ATP-producing breakdown of organic molecules?

    Câu trả lời

    cellular respiration

  264. Thẻ 264

    Câu hỏi

    Which term describes the cytosolic splitting of glucose into pyruvate?

    Câu trả lời

    glycolysis

  265. Thẻ 265

    Câu hỏi

    Which term describes the three-carbon product of glycolysis?

    Câu trả lời

    pyruvate

  266. Thẻ 266

    Câu hỏi

    What is aerobic respiration?

    Câu trả lời

    Respiration that uses oxygen as the final electron acceptor and produces much more ATP than fermentation.

  267. Thẻ 267

    Câu hỏi

    What is anaerobic metabolism?

    Câu trả lời

    ATP-producing metabolism that proceeds without oxygen.

  268. Thẻ 268

    Câu hỏi

    What is fermentation?

    Câu trả lời

    An anaerobic pathway that regenerates oxidized electron carriers so glycolysis can continue.

  269. Thẻ 269

    Câu hỏi

    What is oxidation?

    Câu trả lời

    Loss of electrons, often accompanied in biology by loss of hydrogen or gain of oxygen.

  270. Thẻ 270

    Câu hỏi

    Which term describes respiration using oxygen as final electron acceptor?

    Câu trả lời

    aerobic respiration

  271. Thẻ 271

    Câu hỏi

    Which term describes ATP-producing metabolism without oxygen?

    Câu trả lời

    anaerobic metabolism

  272. Thẻ 272

    Câu hỏi

    Which term describes anaerobic regeneration of electron carriers after glycolysis?

    Câu trả lời

    fermentation

  273. Thẻ 273

    Câu hỏi

    Which term describes loss of electrons?

    Câu trả lời

    oxidation

  274. Thẻ 274

    Câu hỏi

    What is reduction?

    Câu trả lời

    Gain of electrons, often accompanied in biology by gain of hydrogen or loss of oxygen.

  275. Thẻ 275

    Câu hỏi

    What is a reduced electron carrier?

    Câu trả lời

    A molecule such as NADH that carries high-energy electrons and hydrogen from one reaction to another.

  276. Thẻ 276

    Câu hỏi

    What is chemiosmosis?

    Câu trả lời

    ATP production driven by ions moving down an electrochemical gradient through ATP synthase.

  277. Thẻ 277

    Câu hỏi

    What is the overall word equation for aerobic respiration of glucose?

    Câu trả lời

    Glucose + oxygen → carbon dioxide + water + energy transferred to ATP and heat.

  278. Thẻ 278

    Câu hỏi

    Which term describes gain of electrons?

    Câu trả lời

    reduction

  279. Thẻ 279

    Câu hỏi

    Which term describes a molecule carrying high-energy electrons between reactions?

    Câu trả lời

    a reduced electron carrier

  280. Thẻ 280

    Câu hỏi

    Which term describes ATP production powered by an ion gradient?

    Câu trả lời

    chemiosmosis

  281. Thẻ 281

    Câu hỏi

    Where does glycolysis occur?

    Câu trả lời

    In the cytosol.

  282. Thẻ 282

    Câu hỏi

    What major stages of aerobic respiration occur in mitochondria?

    Câu trả lời

    Pyruvate oxidation and the citric acid cycle occur in the matrix; electron transport and chemiosmosis occur at the inner membrane.

  283. Thẻ 283

    Câu hỏi

    What is oxygen's direct role in aerobic respiration?

    Câu trả lời

    It accepts electrons and hydrogen ions at the end of the electron transport chain, forming water.

  284. Thẻ 284

    Câu hỏi

    Why does aerobic respiration yield much more ATP per glucose than fermentation?

    Câu trả lời

    It transfers electrons through an electron transport chain and uses oxidative phosphorylation, extracting far more of glucose's energy.

  285. Thẻ 285

    Câu hỏi

    What is the purpose of lactate formation in oxygen-limited animal cells?

    Câu trả lời

    It regenerates NAD⁺ so glycolysis can continue producing a small amount of ATP.

  286. Thẻ 286

    Câu hỏi

    What products are formed during alcoholic fermentation in yeast?

    Câu trả lời

    Ethanol and carbon dioxide, while NAD⁺ is regenerated.

  287. Thẻ 287

    Câu hỏi

    Why is some energy released by respiration transferred as heat rather than captured in ATP?

    Câu trả lời

    Energy conversions are not fully efficient, so part of the chemical energy becomes disordered molecular motion.

  288. Thẻ 288

    Câu hỏi

    What is substrate-level phosphorylation?

    Câu trả lời

    Direct transfer of a phosphate group from a metabolic intermediate to ADP to form ATP.

  289. Thẻ 289

    Câu hỏi

    How does electron transport lead to ATP synthesis in mitochondria?

    Câu trả lời

    Electron energy pumps protons across the inner membrane; proton flow back through ATP synthase drives ATP formation.

  290. Thẻ 290

    Câu hỏi

    Why can intense exercise increase lactate production?

    Câu trả lời

    ATP demand can exceed oxygen delivery and aerobic capacity, so cells regenerate NAD⁺ through lactate formation to sustain glycolysis.

  291. Thẻ 291

    Câu hỏi

    What is photosynthesis?

    Câu trả lời

    Conversion of light energy into chemical energy used to synthesize organic molecules from carbon dioxide.

  292. Thẻ 292

    Câu hỏi

    What is chlorophyll?

    Câu trả lời

    A green pigment that absorbs light energy for photosynthesis.

  293. Thẻ 293

    Câu hỏi

    What is an absorption spectrum?

    Câu trả lời

    A graph showing how strongly a pigment absorbs different wavelengths of light.

  294. Thẻ 294

    Câu hỏi

    What is an action spectrum?

    Câu trả lời

    A graph showing the rate or effectiveness of photosynthesis at different wavelengths.

  295. Thẻ 295

    Câu hỏi

    Which term describes light-driven synthesis of organic molecules from carbon dioxide?

    Câu trả lời

    photosynthesis

  296. Thẻ 296

    Câu hỏi

    Which term describes the principal green photosynthetic pigment?

    Câu trả lời

    chlorophyll

  297. Thẻ 297

    Câu hỏi

    Which term describes a graph of pigment absorption versus wavelength?

    Câu trả lời

    an absorption spectrum

  298. Thẻ 298

    Câu hỏi

    Which term describes a graph of photosynthetic effectiveness versus wavelength?

    Câu trả lời

    an action spectrum

  299. Thẻ 299

    Câu hỏi

    What is photolysis of water?

    Câu trả lời

    Light-driven splitting of water that supplies electrons and hydrogen ions and releases oxygen.

  300. Thẻ 300

    Câu hỏi

    What are light-dependent reactions?

    Câu trả lời

    Photosynthetic reactions that use light to generate ATP and reduced electron carriers while releasing oxygen.

  301. Thẻ 301

    Câu hỏi

    What is the Calvin cycle?

    Câu trả lời

    A set of chloroplast reactions that uses ATP and reduced electron carriers to convert carbon dioxide into carbohydrate precursors.

  302. Thẻ 302

    Câu hỏi

    What is carbon fixation?

    Câu trả lời

    Incorporation of inorganic carbon dioxide into an organic molecule.

  303. Thẻ 303

    Câu hỏi

    Which term describes light-driven splitting of water?

    Câu trả lời

    photolysis of water

  304. Thẻ 304

    Câu hỏi

    Which term describes photosynthetic reactions that directly capture light energy?

    Câu trả lời

    light-dependent reactions

  305. Thẻ 305

    Câu hỏi

    Which term describes the carbon-reduction cycle of photosynthesis?

    Câu trả lời

    the Calvin cycle

  306. Thẻ 306

    Câu hỏi

    Which term describes incorporation of carbon dioxide into organic matter?

    Câu trả lời

    carbon fixation

  307. Thẻ 307

    Câu hỏi

    What is the role of a stoma in photosynthesis?

    Câu trả lời

    A pore in the leaf epidermis that regulates carbon-dioxide entry as well as water loss.

  308. Thẻ 308

    Câu hỏi

    What is a limiting factor of photosynthesis?

    Câu trả lời

    The environmental factor whose availability currently restricts the photosynthetic rate.

  309. Thẻ 309

    Câu hỏi

    What is the light compensation point?

    Câu trả lời

    The light intensity at which photosynthetic carbon uptake equals respiratory carbon release.

  310. Thẻ 310

    Câu hỏi

    What is the overall word equation for oxygenic photosynthesis?

    Câu trả lời

    Carbon dioxide + water → carbohydrate + oxygen, using light energy.

  311. Thẻ 311

    Câu hỏi

    Which term describes the regulated leaf pore controlling carbon-dioxide entry for photosynthesis?

    Câu trả lời

    a stoma

  312. Thẻ 312

    Câu hỏi

    Which term describes the factor currently restricting photosynthetic rate?

    Câu trả lời

    a limiting factor

  313. Thẻ 313

    Câu hỏi

    Which term describes the light level where photosynthesis and respiration balance?

    Câu trả lời

    the light compensation point

  314. Thẻ 314

    Câu hỏi

    Where do the main stages of photosynthesis occur in a chloroplast?

    Câu trả lời

    Light-dependent reactions occur in thylakoid membranes; carbon-fixation reactions occur in the stroma.

  315. Thẻ 315

    Câu hỏi

    What energy conversion occurs during photosynthesis?

    Câu trả lời

    Light energy is converted into chemical energy stored first in ATP and reduced carriers and ultimately in organic molecules.

  316. Thẻ 316

    Câu hỏi

    From which reactant does the oxygen released by photosynthesis originate?

    Câu trả lời

    Water.

  317. Thẻ 317

    Câu hỏi

    What role does RuBisCO play in photosynthesis?

    Câu trả lời

    It catalyzes fixation of carbon dioxide by adding it to an organic acceptor molecule.

  318. Thẻ 318

    Câu hỏi

    What tradeoff is controlled when stomata open?

    Câu trả lời

    Opening permits carbon dioxide entry but increases water loss by transpiration.

  319. Thẻ 319

    Câu hỏi

    Name three leaf features that support photosynthesis.

    Câu trả lời

    A broad surface captures light, a thin structure shortens diffusion paths, and veins supply water and remove sugars; chloroplast-rich cells and stomata also help.

  320. Thẻ 320

    Câu hỏi

    What can a plant do with carbohydrate made by photosynthesis?

    Câu trả lời

    Use it in respiration, convert it to storage or structural carbohydrates, or use its carbon to make lipids, amino acids, and other molecules.

  321. Thẻ 321

    Câu hỏi

    How are products of the light-dependent reactions used in carbon fixation?

    Câu trả lời

    ATP supplies energy and NADPH supplies reducing power for conversion of fixed carbon into carbohydrate precursors.

  322. Thẻ 322

    Câu hỏi

    Why does increasing light intensity eventually stop increasing photosynthetic rate?

    Câu trả lời

    Another factor, such as carbon dioxide supply, temperature, or biochemical capacity, becomes limiting.

  323. Thẻ 323

    Câu hỏi

    How can increasing carbon dioxide concentration affect photosynthetic rate?

    Câu trả lời

    It can increase the rate until another factor becomes limiting.

  324. Thẻ 324

    Câu hỏi

    Why does photosynthetic rate usually have a temperature optimum?

    Câu trả lời

    Enzyme-controlled reactions accelerate with temperature up to an optimum, then decline as enzymes and membranes lose effective function.

  325. Thẻ 325

    Câu hỏi

    Why does an action spectrum broadly resemble the combined absorption spectra of photosynthetic pigments?

    Câu trả lời

    Wavelengths absorbed by the pigments supply more energy for photosynthesis than poorly absorbed wavelengths.

  326. Thẻ 326

    Câu hỏi

    What is semiconservative replication?

    Câu trả lời

    DNA replication in which each daughter molecule contains one parental strand and one newly synthesized strand.

  327. Thẻ 327

    Câu hỏi

    What is DNA helicase?

    Câu trả lời

    An enzyme that unwinds the double helix and separates the strands by disrupting base pairing.

  328. Thẻ 328

    Câu hỏi

    What is DNA polymerase?

    Câu trả lời

    An enzyme that adds nucleotides to a growing DNA strand using a template.

  329. Thẻ 329

    Câu hỏi

    What is a primer?

    Câu trả lời

    A short nucleic-acid segment providing a free 3′ end from which DNA polymerase can extend.

  330. Thẻ 330

    Câu hỏi

    Which term describes replication producing one old and one new strand per DNA molecule?

    Câu trả lời

    semiconservative replication

  331. Thẻ 331

    Câu hỏi

    Which term describes the enzyme that separates DNA strands?

    Câu trả lời

    DNA helicase

  332. Thẻ 332

    Câu hỏi

    Which term describes the enzyme that builds DNA from a template?

    Câu trả lời

    DNA polymerase

  333. Thẻ 333

    Câu hỏi

    Which term describes the short segment providing a starting 3′ end?

    Câu trả lời

    a primer

  334. Thẻ 334

    Câu hỏi

    What is the leading strand?

    Câu trả lời

    The new DNA strand synthesized continuously toward the replication fork.

  335. Thẻ 335

    Câu hỏi

    What is the lagging strand?

    Câu trả lời

    The new DNA strand synthesized discontinuously away from the replication fork.

  336. Thẻ 336

    Câu hỏi

    What is an Okazaki fragment?

    Câu trả lời

    A short DNA segment synthesized on the lagging strand.

  337. Thẻ 337

    Câu hỏi

    What is DNA ligase?

    Câu trả lời

    An enzyme that seals breaks in the sugar-phosphate backbone, joining DNA fragments.

  338. Thẻ 338

    Câu hỏi

    Which term describes the continuously synthesized daughter strand?

    Câu trả lời

    the leading strand

  339. Thẻ 339

    Câu hỏi

    Which term describes the discontinuously synthesized daughter strand?

    Câu trả lời

    the lagging strand

  340. Thẻ 340

    Câu hỏi

    Which term describes a short newly made segment of lagging-strand DNA?

    Câu trả lời

    an Okazaki fragment

  341. Thẻ 341

    Câu hỏi

    Which term describes the enzyme that joins DNA fragments by sealing the backbone?

    Câu trả lời

    DNA ligase

  342. Thẻ 342

    Câu hỏi

    How does complementary base pairing ensure accurate DNA copying?

    Câu trả lời

    Each template base specifies the nucleotide added opposite it: A pairs with T, and C pairs with G.

  343. Thẻ 343

    Câu hỏi

    Why does DNA polymerase synthesize DNA only 5′ to 3′?

    Câu trả lời

    It can add a nucleotide only to the free 3′ hydroxyl group of the growing strand.

  344. Thẻ 344

    Câu hỏi

    When in the cell cycle is nuclear DNA replicated?

    Câu trả lời

    During S phase of interphase, before cell division.

  345. Thẻ 345

    Câu hỏi

    How can a replication error become a permanent mutation?

    Câu trả lời

    If it escapes proofreading and repair, the altered sequence can be copied in later cell generations.

  346. Thẻ 346

    Câu hỏi

    Why are leading and lagging strands synthesized differently?

    Câu trả lời

    The templates are antiparallel while DNA polymerase works only 5′ to 3′, forcing one strand to be made discontinuously.

  347. Thẻ 347

    Câu hỏi

    How do proofreading and repair reduce replication errors?

    Câu trả lời

    Incorrectly paired nucleotides are recognized, removed, and replaced before or after replication continues.

  348. Thẻ 348

    Câu hỏi

    What three repeating steps amplify DNA in PCR?

    Câu trả lời

    Strand separation by heating, primer annealing during cooling, and DNA extension by a heat-stable polymerase.

  349. Thẻ 349

    Câu hỏi

    What determines which DNA region PCR amplifies?

    Câu trả lời

    The sequences and positions of the two primers flanking the target region.

  350. Thẻ 350

    Câu hỏi

    What is transcription?

    Câu trả lời

    Synthesis of RNA from a DNA template.

  351. Thẻ 351

    Câu hỏi

    What is RNA polymerase?

    Câu trả lời

    The enzyme that synthesizes RNA complementary to a DNA template strand.

  352. Thẻ 352

    Câu hỏi

    What is messenger RNA?

    Câu trả lời

    RNA carrying a coding sequence from DNA to ribosomes.

  353. Thẻ 353

    Câu hỏi

    What is a codon?

    Câu trả lời

    A three-base sequence in mRNA that specifies an amino acid or a translation signal.

  354. Thẻ 354

    Câu hỏi

    Which term describes RNA synthesis from DNA?

    Câu trả lời

    transcription

  355. Thẻ 355

    Câu hỏi

    Which term describes the enzyme that builds RNA from a DNA template?

    Câu trả lời

    RNA polymerase

  356. Thẻ 356

    Câu hỏi

    Which term describes RNA that carries coding information to ribosomes?

    Câu trả lời

    messenger RNA

  357. Thẻ 357

    Câu hỏi

    Which term describes a three-base mRNA unit?

    Câu trả lời

    a codon

  358. Thẻ 358

    Câu hỏi

    What is translation?

    Câu trả lời

    Synthesis of a polypeptide using the codon sequence of mRNA.

  359. Thẻ 359

    Câu hỏi

    What does a ribosome do during translation?

    Câu trả lời

    It reads mRNA and catalyzes polypeptide synthesis using its rRNA-protein machinery.

  360. Thẻ 360

    Câu hỏi

    What is transfer RNA?

    Câu trả lời

    RNA that carries a specific amino acid and pairs its anticodon with an mRNA codon.

  361. Thẻ 361

    Câu hỏi

    What is an anticodon?

    Câu trả lời

    A three-base tRNA sequence complementary to an mRNA codon.

  362. Thẻ 362

    Câu hỏi

    Which term describes polypeptide synthesis from an mRNA sequence?

    Câu trả lời

    translation

  363. Thẻ 363

    Câu hỏi

    Which term describes the translation complex that reads mRNA and builds a polypeptide?

    Câu trả lời

    a ribosome

  364. Thẻ 364

    Câu hỏi

    Which term describes the adaptor RNA carrying an amino acid?

    Câu trả lời

    transfer RNA

  365. Thẻ 365

    Câu hỏi

    Which term describes the tRNA triplet that pairs with a codon?

    Câu trả lời

    an anticodon

  366. Thẻ 366

    Câu hỏi

    What is the genetic code?

    Câu trả lời

    The set of rules relating mRNA codons to amino acids and translation signals.

  367. Thẻ 367

    Câu hỏi

    What are start and stop codons?

    Câu trả lời

    mRNA signals that establish the reading frame or terminate translation.

  368. Thẻ 368

    Câu hỏi

    Where do transcription and translation occur in a eukaryotic cell?

    Câu trả lời

    Transcription occurs in the nucleus; translation occurs on ribosomes in the cytoplasm or on rough ER.

  369. Thẻ 369

    Câu hỏi

    How is an mRNA sequence related to its DNA template strand?

    Câu trả lời

    It is complementary and antiparallel, with uracil in RNA opposite adenine in DNA.

  370. Thẻ 370

    Câu hỏi

    Which term describes the codon-to-amino-acid rule set?

    Câu trả lời

    the genetic code

  371. Thẻ 371

    Câu hỏi

    Which term describes codons that begin or end translation?

    Câu trả lời

    start and stop codons

  372. Thẻ 372

    Câu hỏi

    What reaction does the ribosome catalyze as a polypeptide grows?

    Câu trả lời

    Formation of peptide bonds between adjacent amino acids.

  373. Thẻ 373

    Câu hỏi

    What does it mean that the genetic code is degenerate?

    Câu trả lời

    Most amino acids are specified by more than one codon.

  374. Thẻ 374

    Câu hỏi

    How can one mRNA produce many polypeptides quickly?

    Câu trả lời

    Multiple ribosomes can translate the same mRNA simultaneously as a polyribosome.

  375. Thẻ 375

    Câu hỏi

    Why is translation not the final step in producing many functional proteins?

    Câu trả lời

    The polypeptide must fold and may undergo cleavage, chemical modification, or assembly with other subunits.

  376. Thẻ 376

    Câu hỏi

    How does mRNA compare with the DNA coding strand?

    Câu trả lời

    It has the same base sequence except that RNA contains uracil where DNA contains thymine.

  377. Thẻ 377

    Câu hỏi

    What happens during eukaryotic RNA splicing?

    Câu trả lời

    Introns are removed and exons are joined to form mature mRNA.

  378. Thẻ 378

    Câu hỏi

    Why must codons be read in the correct reading frame?

    Câu trả lời

    Changing the starting position changes every downstream triplet and therefore the amino-acid sequence.

  379. Thẻ 379

    Câu hỏi

    How is the correct amino acid matched to each mRNA codon?

    Câu trả lời

    Each tRNA is charged with a particular amino acid, and its anticodon pairs with the complementary codon.

  380. Thẻ 380

    Câu hỏi

    How can a base substitution affect a protein?

    Câu trả lời

    It may be silent, change one amino acid, create a stop codon, or sometimes alter RNA processing.

  381. Thẻ 381

    Câu hỏi

    What is a mutation?

    Câu trả lời

    A change in a DNA sequence or chromosome structure that can be passed to daughter cells.

  382. Thẻ 382

    Câu hỏi

    What is a base substitution?

    Câu trả lời

    Replacement of one nucleotide pair by another.

  383. Thẻ 383

    Câu hỏi

    What is an insertion mutation?

    Câu trả lời

    Addition of one or more nucleotides to a DNA sequence.

  384. Thẻ 384

    Câu hỏi

    What is a deletion mutation?

    Câu trả lời

    Loss of one or more nucleotides from a DNA sequence.

  385. Thẻ 385

    Câu hỏi

    Which term describes a lasting DNA-sequence or chromosome change?

    Câu trả lời

    a mutation

  386. Thẻ 386

    Câu hỏi

    Which term describes replacement of one DNA base pair?

    Câu trả lời

    a base substitution

  387. Thẻ 387

    Câu hỏi

    Which term describes addition of nucleotides to DNA?

    Câu trả lời

    an insertion mutation

  388. Thẻ 388

    Câu hỏi

    Which term describes loss of nucleotides from DNA?

    Câu trả lời

    a deletion mutation

  389. Thẻ 389

    Câu hỏi

    What is a frameshift mutation?

    Câu trả lời

    A coding-sequence insertion or deletion not divisible by three that changes downstream codon grouping.

  390. Thẻ 390

    Câu hỏi

    What is a silent mutation?

    Câu trả lời

    A sequence change that does not alter the encoded amino acid.

  391. Thẻ 391

    Câu hỏi

    What is a missense mutation?

    Câu trả lời

    A mutation that changes a codon so a different amino acid is incorporated.

  392. Thẻ 392

    Câu hỏi

    What is a nonsense mutation?

    Câu trả lời

    A mutation that changes an amino-acid codon into a stop codon.

  393. Thẻ 393

    Câu hỏi

    Which term describes a mutation that shifts downstream codon grouping?

    Câu trả lời

    a frameshift mutation

  394. Thẻ 394

    Câu hỏi

    Which term describes a coding change that leaves the amino acid unchanged?

    Câu trả lời

    a silent mutation

  395. Thẻ 395

    Câu hỏi

    Which term describes a mutation causing one amino-acid substitution?

    Câu trả lời

    a missense mutation

  396. Thẻ 396

    Câu hỏi

    Which term describes a mutation creating a premature stop codon?

    Câu trả lời

    a nonsense mutation

  397. Thẻ 397

    Câu hỏi

    How do germline and somatic mutations differ in inheritance?

    Câu trả lời

    Germline mutations can enter gametes and be inherited; somatic mutations affect a cell lineage within the individual.

  398. Thẻ 398

    Câu hỏi

    What can cause mutations?

    Câu trả lời

    Replication errors, spontaneous chemical changes, radiation, and mutagenic chemicals can alter DNA.

  399. Thẻ 399

    Câu hỏi

    How does DNA repair protect genome stability?

    Câu trả lời

    Repair systems detect damaged or mismatched DNA and restore the correct structure or sequence when possible.

  400. Thẻ 400

    Câu hỏi

    Why are mutations essential to evolution despite often being neutral or harmful?

    Câu trả lời

    They create new alleles, providing the heritable variation on which selection and drift act.

  401. Thẻ 401

    Câu hỏi

    What is the basic role of guide RNA in CRISPR gene editing?

    Câu trả lời

    It directs a nuclease to a complementary DNA sequence.

  402. Thẻ 402

    Câu hỏi

    Why can the same type of DNA mutation have effects ranging from none to severe?

    Câu trả lời

    Effects depend on location, genetic-code redundancy, protein role, cell type, and environmental context.

  403. Thẻ 403

    Câu hỏi

    How can accumulated mutations contribute to cancer?

    Câu trả lời

    Mutations can activate growth-promoting genes or disable genes that restrain division, repair DNA, or trigger cell death.

  404. Thẻ 404

    Câu hỏi

    Why can repairing a CRISPR-induced DNA break produce different editing outcomes?

    Câu trả lời

    Different cellular repair pathways may disrupt the target sequence or use a supplied template for a specific change.

  405. Thẻ 405

    Câu hỏi

    What is an off-target effect in gene editing?

    Câu trả lời

    An unintended DNA change at a site sufficiently similar to the intended target.

  406. Thẻ 406

    Câu hỏi

    Why does heritable human genome editing raise additional ethical concerns?

    Câu trả lời

    Changes could pass to future generations who cannot consent, with uncertain long-term biological and social effects.

  407. Thẻ 407

    Câu hỏi

    What is the cell cycle?

    Câu trả lời

    The ordered sequence of cell growth, DNA replication, nuclear division, and cell division.

  408. Thẻ 408

    Câu hỏi

    What is interphase?

    Câu trả lời

    The period of growth, normal activity, and DNA replication between nuclear divisions.

  409. Thẻ 409

    Câu hỏi

    What is mitosis?

    Câu trả lời

    Nuclear division that usually produces genetically equivalent daughter nuclei.

  410. Thẻ 410

    Câu hỏi

    What is cytokinesis?

    Câu trả lời

    Division of the cytoplasm to form separate daughter cells.

  411. Thẻ 411

    Câu hỏi

    Which term describes the ordered sequence from one cell division to the next?

    Câu trả lời

    the cell cycle

  412. Thẻ 412

    Câu hỏi

    Which term describes the growth and DNA-replication period between divisions?

    Câu trả lời

    interphase

  413. Thẻ 413

    Câu hỏi

    Which term describes division producing genetically equivalent nuclei?

    Câu trả lời

    mitosis

  414. Thẻ 414

    Câu hỏi

    Which term describes physical division of the cytoplasm?

    Câu trả lời

    cytokinesis

  415. Thẻ 415

    Câu hỏi

    What is a chromosome?

    Câu trả lời

    One DNA molecule packaged with associated proteins.

  416. Thẻ 416

    Câu hỏi

    What are sister chromatids?

    Câu trả lời

    The two replicated copies of a chromosome joined before separation.

  417. Thẻ 417

    Câu hỏi

    What is a centromere?

    Câu trả lời

    The chromosome region that holds sister chromatids together and organizes kinetochore attachment.

  418. Thẻ 418

    Câu hỏi

    What is the mitotic spindle?

    Câu trả lời

    A microtubule system that attaches to and separates chromosomes during cell division.

  419. Thẻ 419

    Câu hỏi

    Which term describes a protein-packaged DNA molecule?

    Câu trả lời

    a chromosome

  420. Thẻ 420

    Câu hỏi

    Which term describes joined replicated copies of one chromosome?

    Câu trả lời

    sister chromatids

  421. Thẻ 421

    Câu hỏi

    Which term describes the chromosome region joining sister chromatids?

    Câu trả lời

    a centromere

  422. Thẻ 422

    Câu hỏi

    Which term describes the chromosome-separating microtubule system?

    Câu trả lời

    the mitotic spindle

  423. Thẻ 423

    Câu hỏi

    What is the basic sequence of mitosis?

    Câu trả lời

    Chromosomes condense, align at the cell equator, sister chromatids separate to opposite poles, and new nuclei form.

  424. Thẻ 424

    Câu hỏi

    Why must DNA replicate before mitosis?

    Câu trả lời

    Each chromosome must have two copies so each daughter nucleus can receive a complete genome.

  425. Thẻ 425

    Câu hỏi

    Why are daughter cells from mitosis usually genetically similar?

    Câu trả lời

    Replicated sister chromatids are separated so each daughter receives one copy of every chromosome.

  426. Thẻ 426

    Câu hỏi

    What are major roles of mitosis in multicellular organisms?

    Câu trả lời

    Growth, tissue repair, cell replacement, and some forms of asexual reproduction.

  427. Thẻ 427

    Câu hỏi

    How do homologous chromosomes differ from sister chromatids?

    Câu trả lời

    Homologs carry the same gene loci but may have different alleles; sister chromatids are replicated copies of one chromosome.

  428. Thẻ 428

    Câu hỏi

    What key outcome distinguishes mitosis from meiosis?

    Câu trả lời

    Mitosis usually preserves chromosome number and similarity; meiosis halves chromosome number and generates genetically varied haploid cells.

  429. Thẻ 429

    Câu hỏi

    How does cytokinesis commonly occur in animal cells?

    Câu trả lời

    A contractile ring tightens the plasma membrane into a cleavage furrow.

  430. Thẻ 430

    Câu hỏi

    How does cytokinesis commonly occur in plant cells?

    Câu trả lời

    Vesicles fuse at the center to form a cell plate that develops into new membranes and a cell wall.

  431. Thẻ 431

    Câu hỏi

    What is the purpose of cell-cycle checkpoints?

    Câu trả lời

    They delay progression when conditions are unsuitable or DNA and chromosome attachment are defective.

  432. Thẻ 432

    Câu hỏi

    How is loss of cell-cycle control related to cancer?

    Câu trả lời

    Cells can divide despite damage or growth restraints, producing an expanding abnormal clone.

  433. Thẻ 433

    Câu hỏi

    What is a gene?

    Câu trả lời

    A DNA sequence that contributes to a functional product and influences a characteristic or cellular process.

  434. Thẻ 434

    Câu hỏi

    What is an allele?

    Câu trả lời

    One of the alternative DNA-sequence forms at a gene locus.

  435. Thẻ 435

    Câu hỏi

    What is a gene locus?

    Câu trả lời

    The physical position of a gene on a chromosome.

  436. Thẻ 436

    Câu hỏi

    What is a genotype?

    Câu trả lời

    The allele combination of an organism at one or more loci.

  437. Thẻ 437

    Câu hỏi

    Which term describes a functional DNA sequence?

    Câu trả lời

    a gene

  438. Thẻ 438

    Câu hỏi

    Which term describes an alternative form of a gene?

    Câu trả lời

    an allele

  439. Thẻ 439

    Câu hỏi

    Which term describes a gene's chromosome position?

    Câu trả lời

    a gene locus

  440. Thẻ 440

    Câu hỏi

    Which term describes an organism's allele combination?

    Câu trả lời

    a genotype

  441. Thẻ 441

    Câu hỏi

    What is a phenotype?

    Câu trả lời

    An observable or measurable trait produced by genotype and environment.

  442. Thẻ 442

    Câu hỏi

    What is homozygous?

    Câu trả lời

    Having two identical alleles at a diploid locus.

  443. Thẻ 443

    Câu hỏi

    What is heterozygous?

    Câu trả lời

    Having two different alleles at a diploid locus.

  444. Thẻ 444

    Câu hỏi

    What is a dominant allele?

    Câu trả lời

    An allele expressed in the phenotype of a heterozygote under a specified inheritance model.

  445. Thẻ 445

    Câu hỏi

    Which term describes an observable trait resulting from genes and environment?

    Câu trả lời

    a phenotype

  446. Thẻ 446

    Câu hỏi

    Which term describes having two identical alleles at a locus?

    Câu trả lời

    homozygous

  447. Thẻ 447

    Câu hỏi

    Which term describes having two different alleles at a locus?

    Câu trả lời

    heterozygous

  448. Thẻ 448

    Câu hỏi

    Which term describes an allele expressed in a heterozygote?

    Câu trả lời

    a dominant allele

  449. Thẻ 449

    Câu hỏi

    What is a recessive allele?

    Câu trả lời

    An allele whose phenotype is masked by a dominant allele in a heterozygote.

  450. Thẻ 450

    Câu hỏi

    What is a genetic carrier?

    Câu trả lời

    An unaffected heterozygote who can transmit a recessive disease allele.

  451. Thẻ 451

    Câu hỏi

    What is a test cross?

    Câu trả lời

    A cross with a homozygous recessive individual used to infer an unknown dominant phenotype's genotype.

  452. Thẻ 452

    Câu hỏi

    What is a pedigree?

    Câu trả lời

    A diagram showing biological relationships and occurrence of a trait across generations.

  453. Thẻ 453

    Câu hỏi

    Which term describes an allele masked in a heterozygote?

    Câu trả lời

    a recessive allele

  454. Thẻ 454

    Câu hỏi

    Which term describes an unaffected heterozygote carrying a recessive disease allele?

    Câu trả lời

    a genetic carrier

  455. Thẻ 455

    Câu hỏi

    Which term describes a cross used to reveal an unknown dominant genotype?

    Câu trả lời

    a test cross

  456. Thẻ 456

    Câu hỏi

    Which term describes a family diagram tracking a trait across generations?

    Câu trả lời

    a pedigree

  457. Thẻ 457

    Câu hỏi

    What does allele segregation mean during gamete formation?

    Câu trả lời

    The two alleles at a diploid locus separate so each gamete receives one.

  458. Thẻ 458

    Câu hỏi

    What does a Punnett square predict?

    Câu trả lời

    Expected genotype and phenotype probabilities from specified parental gametes, not guaranteed family outcomes.

  459. Thẻ 459

    Câu hỏi

    What phenotypic ratio is expected from Aa × Aa with complete dominance?

    Câu trả lời

    Approximately 3 dominant phenotype : 1 recessive phenotype.

  460. Thẻ 460

    Câu hỏi

    What genotypic ratio is expected from Aa × Aa?

    Câu trả lời

    1 AA : 2 Aa : 1 aa.

  461. Thẻ 461

    Câu hỏi

    What happens in codominance?

    Câu trả lời

    Both alleles contribute distinctly to the heterozygous phenotype.

  462. Thẻ 462

    Câu hỏi

    What happens in incomplete dominance?

    Câu trả lời

    The heterozygote has a phenotype intermediate between the two homozygotes.

  463. Thẻ 463

    Câu hỏi

    How can environment affect phenotype without changing genotype?

    Câu trả lời

    Conditions alter development, physiology, or gene expression, changing the observed trait.

  464. Thẻ 464

    Câu hỏi

    What is the ultimate source of new alleles?

    Câu trả lời

    Mutation.

  465. Thẻ 465

    Câu hỏi

    Why are X-linked recessive traits more common in XY individuals?

    Câu trả lời

    They have only one X chromosome, so one recessive allele on it can determine the phenotype.

  466. Thẻ 466

    Câu hỏi

    When is the product rule used in genetic probability?

    Câu trả lời

    For independent events that must both occur; multiply their probabilities.

  467. Thẻ 467

    Câu hỏi

    When is the sum rule used in genetic probability?

    Câu trả lời

    For mutually exclusive alternative outcomes; add their probabilities.

  468. Thẻ 468

    Câu hỏi

    Why do polygenic traits often show continuous variation?

    Câu trả lời

    Many loci contribute small effects, creating many possible genotypes and phenotypes, often further influenced by environment.

  469. Thẻ 469

    Câu hỏi

    What pedigree pattern can suggest an autosomal recessive trait?

    Câu trả lời

    Unaffected parents can have affected children, and all sexes are affected at similar frequencies.

  470. Thẻ 470

    Câu hỏi

    What is a species?

    Câu trả lời

    A group of organisms whose members can potentially interbreed and produce fertile offspring under natural conditions.

  471. Thẻ 471

    Câu hỏi

    What is binomial nomenclature?

    Câu trả lời

    The two-part scientific naming system using a genus name followed by a specific epithet.

  472. Thẻ 472

    Câu hỏi

    What is taxonomy?

    Câu trả lời

    The naming and classification of organisms.

  473. Thẻ 473

    Câu hỏi

    What is a biological domain?

    Câu trả lời

    The broadest commonly used taxonomic rank, separating Bacteria, Archaea, and Eukarya.

  474. Thẻ 474

    Câu hỏi

    Which term describes a naturally interbreeding group producing fertile offspring?

    Câu trả lời

    a species

  475. Thẻ 475

    Câu hỏi

    Which term describes the genus-plus-specific-epithet naming system?

    Câu trả lời

    binomial nomenclature

  476. Thẻ 476

    Câu hỏi

    Which term describes the science of naming and classifying organisms?

    Câu trả lời

    taxonomy

  477. Thẻ 477

    Câu hỏi

    Which term describes the broadest common taxonomic rank?

    Câu trả lời

    a biological domain

  478. Thẻ 478

    Câu hỏi

    What is biodiversity?

    Câu trả lời

    Variation of life at genetic, species, and ecosystem levels.

  479. Thẻ 479

    Câu hỏi

    What is an autotroph?

    Câu trả lời

    An organism that makes organic compounds from inorganic carbon using light or chemical energy.

  480. Thẻ 480

    Câu hỏi

    What is a heterotroph?

    Câu trả lời

    An organism that obtains organic carbon by consuming other organisms or their products.

    Luminous sequence of molecular forms, a cell, a leaf and animal silhouette, and a water ecosystem on a dark blue background.

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  481. Thẻ 481

    Câu hỏi

    What is a unicellular organism?

    Câu trả lời

    An organism consisting of one cell that carries out all essential life functions.

  482. Thẻ 482

    Câu hỏi

    Which term describes variation of life across genes, species, and ecosystems?

    Câu trả lời

    biodiversity

  483. Thẻ 483

    Câu hỏi

    Which term describes an organism that builds organic matter from inorganic carbon?

    Câu trả lời

    an autotroph

  484. Thẻ 484

    Câu hỏi

    Which term describes an organism obtaining organic carbon from other organisms?

    Câu trả lời

    a heterotroph

  485. Thẻ 485

    Câu hỏi

    Which term describes an organism made of one cell?

    Câu trả lời

    a unicellular organism

  486. Thẻ 486

    Câu hỏi

    What is a multicellular organism?

    Câu trả lời

    An organism composed of many cooperating cells, often with specialized cell types.

  487. Thẻ 487

    Câu hỏi

    What is a karyotype?

    Câu trả lời

    An ordered display of chromosomes used to examine their number and large-scale structure.

  488. Thẻ 488

    Câu hỏi

    What broad feature distinguishes both Bacteria and Archaea from Eukarya?

    Câu trả lời

    Their cells lack a nucleus and other membrane-bound organelles.

  489. Thẻ 489

    Câu hỏi

    What features characterize most plant cells?

    Câu trả lời

    Cellulose walls, chloroplasts in photosynthetic tissues, and large vacuoles are typical features.

  490. Thẻ 490

    Câu hỏi

    Which term describes an organism made of many cooperating cells?

    Câu trả lời

    a multicellular organism

  491. Thẻ 491

    Câu hỏi

    Which term describes an ordered display of an individual's chromosomes?

    Câu trả lời

    a karyotype

  492. Thẻ 492

    Câu hỏi

    How do fungi obtain nutrients?

    Câu trả lời

    They secrete digestive enzymes and absorb soluble products; their cells usually have chitin-containing walls.

  493. Thẻ 493

    Câu hỏi

    What distinguishes animal nutrition and cell structure?

    Câu trả lời

    Animals ingest organic material, and their cells lack cell walls and chloroplasts.

  494. Thẻ 494

    Câu hỏi

    Why are scientific names useful across languages?

    Câu trả lời

    A standardized name identifies the same organism internationally and reduces ambiguity from local common names.

  495. Thẻ 495

    Câu hỏi

    Why can genetic diversity improve a population's resilience?

    Câu trả lời

    More heritable variation increases the chance that some individuals tolerate new diseases or environmental changes.

  496. Thẻ 496

    Câu hỏi

    What does ecosystem diversity measure?

    Câu trả lời

    The variety of habitats, communities, and ecological processes within a region.

  497. Thẻ 497

    Câu hỏi

    Why are Archaea classified separately from Bacteria?

    Câu trả lời

    They differ in genetic sequences, membrane chemistry, cell-wall composition, and aspects of molecular machinery.

  498. Thẻ 498

    Câu hỏi

    Why is the biological species concept difficult to apply to fossils or asexual organisms?

    Câu trả lời

    Their ability to interbreed and produce fertile offspring cannot be tested in the usual way.

  499. Thẻ 499

    Câu hỏi

    Does a larger chromosome number necessarily mean a more complex organism?

    Câu trả lời

    No. Chromosome number varies through fusion, fission, and duplication and does not directly measure biological complexity.

  500. Thẻ 500

    Câu hỏi

    Does genome size reliably predict organismal complexity?

    Câu trả lời

    No. Large amounts of noncoding and repeated DNA make genome size a poor simple measure of complexity.

  501. Thẻ 501

    Câu hỏi

    What evidence can be combined when classifying organisms?

    Câu trả lời

    Molecular sequences, cell structure, anatomy, development, physiology, and reproductive evidence can all contribute.

  502. Thẻ 502

    Câu hỏi

    What is gas exchange?

    Câu trả lời

    Diffusion of respiratory gases between an organism and its environment or transport fluid.

  503. Thẻ 503

    Câu hỏi

    What is ventilation?

    Câu trả lời

    Bulk movement of air or water over a gas-exchange surface.

  504. Thẻ 504

    Câu hỏi

    What is an alveolus?

    Câu trả lời

    A microscopic air sac in the lung where gases diffuse between air and blood.

  505. Thẻ 505

    Câu hỏi

    What is pulmonary surfactant?

    Câu trả lời

    A substance lining alveoli that lowers surface tension and reduces collapse.

  506. Thẻ 506

    Câu hỏi

    Which term describes diffusion of oxygen and carbon dioxide across a respiratory surface?

    Câu trả lời

    gas exchange

  507. Thẻ 507

    Câu hỏi

    Which term describes bulk movement of respiratory medium over an exchange surface?

    Câu trả lời

    ventilation

  508. Thẻ 508

    Câu hỏi

    Which term describes a microscopic lung air sac?

    Câu trả lời

    an alveolus

  509. Thẻ 509

    Câu hỏi

    Which term describes the alveolar lining that lowers surface tension?

    Câu trả lời

    pulmonary surfactant

  510. Thẻ 510

    Câu hỏi

    What is the diaphragm?

    Câu trả lời

    A sheet of skeletal muscle whose contraction increases thoracic volume during inhalation.

  511. Thẻ 511

    Câu hỏi

    What is tidal volume?

    Câu trả lời

    The volume of air moved in or out during a normal breath.

  512. Thẻ 512

    Câu hỏi

    What is a stoma?

    Câu trả lời

    A regulated epidermal pore through which gases diffuse in leaves.

  513. Thẻ 513

    Câu hỏi

    What is countercurrent exchange?

    Câu trả lời

    Exchange between fluids moving in opposite directions, maintaining a gradient along most of the surface.

  514. Thẻ 514

    Câu hỏi

    Which term describes the muscle sheet that expands the thorax during inhalation?

    Câu trả lời

    the diaphragm

  515. Thẻ 515

    Câu hỏi

    Which term describes air volume moved in one normal breath?

    Câu trả lời

    tidal volume

  516. Thẻ 516

    Câu hỏi

    Which term describes a regulated leaf gas-exchange pore?

    Câu trả lời

    a stoma

  517. Thẻ 517

    Câu hỏi

    Which term describes opposite fluid flow that maintains an exchange gradient?

    Câu trả lời

    countercurrent exchange

  518. Thẻ 518

    Câu hỏi

    What features make an efficient gas-exchange surface?

    Câu trả lời

    Large area, short diffusion distance, permeability, and maintained concentration gradients.

  519. Thẻ 519

    Câu hỏi

    How is a steep oxygen gradient maintained across alveoli?

    Câu trả lời

    Ventilation replenishes alveolar oxygen and blood flow removes absorbed oxygen.

  520. Thẻ 520

    Câu hỏi

    How does diaphragm contraction cause inhalation?

    Câu trả lời

    Thoracic volume increases, lung pressure falls below atmospheric pressure, and air flows inward.

  521. Thẻ 521

    Câu hỏi

    What drives quiet exhalation?

    Câu trả lời

    The diaphragm relaxes and elastic recoil reduces thoracic and lung volume, raising pressure and pushing air out.

  522. Thẻ 522

    Câu hỏi

    Why do ventilation rate and depth increase during exercise?

    Câu trả lời

    They increase oxygen uptake and carbon dioxide removal to support higher cellular respiration.

  523. Thẻ 523

    Câu hỏi

    How does leaf structure shorten the pathway for carbon dioxide diffusion?

    Câu trả lời

    Stomata open into air spaces, and mesophyll cells expose moist surfaces close to those spaces.

  524. Thẻ 524

    Câu hỏi

    Why does carbon dioxide diffuse from tissues into blood?

    Câu trả lời

    Respiring cells produce carbon dioxide, making its partial pressure higher in tissues than in incoming blood.

  525. Thẻ 525

    Câu hỏi

    How does countercurrent flow improve oxygen uptake at fish gills?

    Câu trả lời

    Blood continually meets water with a higher oxygen concentration, preserving diffusion along the lamella.

  526. Thẻ 526

    Câu hỏi

    Why does closing stomata reduce both water loss and photosynthesis?

    Câu trả lời

    It limits water-vapor diffusion out but also restricts carbon dioxide diffusion into the leaf.

  527. Thẻ 527

    Câu hỏi

    What is a circulatory system?

    Câu trả lời

    A transport system that moves a fluid carrying gases, nutrients, wastes, hormones, and heat through an organism.

  528. Thẻ 528

    Câu hỏi

    What is an artery?

    Câu trả lời

    A blood vessel carrying blood away from the heart under relatively high pressure.

  529. Thẻ 529

    Câu hỏi

    What is a vein?

    Câu trả lời

    A blood vessel carrying blood toward the heart, usually with low pressure and often valves.

  530. Thẻ 530

    Câu hỏi

    What is a capillary?

    Câu trả lời

    A microscopic thin-walled vessel where substances exchange between blood and tissues.

  531. Thẻ 531

    Câu hỏi

    Which term describes an internal fluid-transport system?

    Câu trả lời

    a circulatory system

  532. Thẻ 532

    Câu hỏi

    Which term describes a vessel carrying blood away from the heart?

    Câu trả lời

    an artery

  533. Thẻ 533

    Câu hỏi

    Which term describes a vessel carrying blood toward the heart?

    Câu trả lời

    a vein

  534. Thẻ 534

    Câu hỏi

    Which term describes a microscopic exchange blood vessel?

    Câu trả lời

    a capillary

  535. Thẻ 535

    Câu hỏi

    What is the cardiac cycle?

    Câu trả lời

    The repeating sequence of heart-chamber contraction and relaxation that pumps blood.

  536. Thẻ 536

    Câu hỏi

    What is hemoglobin?

    Câu trả lời

    An iron-containing protein in red blood cells that binds oxygen reversibly.

  537. Thẻ 537

    Câu hỏi

    What is xylem?

    Câu trả lời

    Plant vascular tissue that transports water and mineral ions and provides structural support.

  538. Thẻ 538

    Câu hỏi

    What is phloem?

    Câu trả lời

    Plant vascular tissue that transports sucrose and other organic solutes between sources and sinks.

  539. Thẻ 539

    Câu hỏi

    Which term describes the repeating pumping sequence of the heart?

    Câu trả lời

    the cardiac cycle

  540. Thẻ 540

    Câu hỏi

    Which term describes the oxygen-carrying protein of red blood cells?

    Câu trả lời

    hemoglobin

  541. Thẻ 541

    Câu hỏi

    Which term describes plant tissue carrying water and minerals?

    Câu trả lời

    xylem

  542. Thẻ 542

    Câu hỏi

    Which term describes plant tissue carrying organic solutes?

    Câu trả lời

    phloem

  543. Thẻ 543

    Câu hỏi

    What is transpiration?

    Câu trả lời

    Loss of water vapor from plant surfaces, mainly through stomata.

  544. Thẻ 544

    Câu hỏi

    What is phloem translocation?

    Câu trả lời

    Movement of organic solutes through phloem from sources to sinks.

  545. Thẻ 545

    Câu hỏi

    How do a source and a sink differ in plant transport?

    Câu trả lời

    A source releases assimilates to phloem; a sink removes them for use or storage.

  546. Thẻ 546

    Câu hỏi

    What makes human circulation a double circulation?

    Câu trả lời

    Blood passes through the heart once in the pulmonary circuit and again in the systemic circuit during one complete journey.

  547. Thẻ 547

    Câu hỏi

    Which term describes water-vapor loss from plant surfaces?

    Câu trả lời

    transpiration

  548. Thẻ 548

    Câu hỏi

    Which term describes movement of organic solutes through phloem?

    Câu trả lời

    phloem translocation

  549. Thẻ 549

    Câu hỏi

    Which term describes the exporting and importing regions of phloem transport?

    Câu trả lời

    source and sink

  550. Thẻ 550

    Câu hỏi

    How is an artery adapted to high pressure?

    Câu trả lời

    It has thick elastic and muscular walls and a relatively narrow lumen.

  551. Thẻ 551

    Câu hỏi

    How is a vein adapted to return low-pressure blood?

    Câu trả lời

    It has a wide lumen, thinner walls, and valves that reduce backflow.

  552. Thẻ 552

    Câu hỏi

    How does capillary structure support exchange?

    Câu trả lời

    One-cell-thick walls give a short diffusion distance; extensive branching gives a large total area; narrow lumens slow flow and keep blood close to tissues.

  553. Thẻ 553

    Câu hỏi

    What determines whether a heart valve opens or closes?

    Câu trả lời

    Pressure differences across the valve.

  554. Thẻ 554

    Câu hỏi

    Trace water from soil to the atmosphere through a plant.

    Câu trả lời

    Soil → root hairs → root tissues → xylem → leaf mesophyll → leaf air spaces → stomata → atmosphere.

  555. Thẻ 555

    Câu hỏi

    Why may root cells use active transport to absorb mineral ions?

    Câu trả lời

    Ion concentrations can be lower in soil than in root cells, so uptake must occur against a gradient.

  556. Thẻ 556

    Câu hỏi

    Why do large multicellular organisms need bulk transport systems?

    Câu trả lời

    Their low surface-area-to-volume ratio and long diffusion distances make diffusion alone too slow for whole-body supply.

  557. Thẻ 557

    Câu hỏi

    Why does hemoglobin unload more oxygen in actively respiring tissues?

    Câu trả lời

    Lower oxygen and often higher carbon dioxide and acidity reduce hemoglobin's oxygen affinity.

  558. Thẻ 558

    Câu hỏi

    How does transpiration pull water upward through xylem?

    Câu trả lời

    Evaporation lowers leaf water potential and creates tension; cohesion transmits the pull through the continuous water column.

  559. Thẻ 559

    Câu hỏi

    How do wind and low humidity generally affect transpiration?

    Câu trả lời

    Both maintain a steep water-vapor gradient outside the leaf, increasing transpiration if stomata remain open.

  560. Thẻ 560

    Câu hỏi

    What drives mass flow in phloem?

    Câu trả lời

    Sugar loading draws in water and raises pressure at a source; unloading lowers pressure at a sink, producing bulk flow.

  561. Thẻ 561

    Câu hỏi

    Can the same plant organ be a source at one time and a sink at another?

    Câu trả lời

    Yes. A storage organ may import sugars while filling and export them later during growth or germination.

  562. Thẻ 562

    Câu hỏi

    What is a neuron?

    Câu trả lời

    An excitable cell specialized to receive, process, and transmit information.

  563. Thẻ 563

    Câu hỏi

    What is a sensory neuron?

    Câu trả lời

    A neuron carrying information from a receptor toward the central nervous system.

  564. Thẻ 564

    Câu hỏi

    What is a motor neuron?

    Câu trả lời

    A neuron carrying commands from the central nervous system to an effector.

  565. Thẻ 565

    Câu hỏi

    What is the resting potential?

    Câu trả lời

    The voltage difference across an unstimulated neuron's membrane, with the inside negative relative to outside.

  566. Thẻ 566

    Câu hỏi

    Which term describes an excitable information-transmitting cell?

    Câu trả lời

    a neuron

  567. Thẻ 567

    Câu hỏi

    Which term describes a neuron carrying receptor information to the CNS?

    Câu trả lời

    a sensory neuron

  568. Thẻ 568

    Câu hỏi

    Which term describes a neuron carrying CNS commands to an effector?

    Câu trả lời

    a motor neuron

  569. Thẻ 569

    Câu hỏi

    Which term describes the negative-inside voltage of an unstimulated neuron?

    Câu trả lời

    the resting potential

  570. Thẻ 570

    Câu hỏi

    What is an action potential?

    Câu trả lời

    A brief, self-propagating reversal and restoration of membrane potential along an excitable membrane.

  571. Thẻ 571

    Câu hỏi

    What is depolarization?

    Câu trả lời

    A change that makes membrane potential less negative, and during an action potential often positive.

  572. Thẻ 572

    Câu hỏi

    What is repolarization?

    Câu trả lời

    Return of membrane potential toward its resting negative value after depolarization.

  573. Thẻ 573

    Câu hỏi

    What is a synapse?

    Câu trả lời

    A junction where one cell communicates with another cell.

  574. Thẻ 574

    Câu hỏi

    Which term describes a brief propagating change in neuron membrane voltage?

    Câu trả lời

    an action potential

  575. Thẻ 575

    Câu hỏi

    Which term describes a membrane-voltage change toward a less negative value?

    Câu trả lời

    depolarization

  576. Thẻ 576

    Câu hỏi

    Which term describes return toward resting membrane voltage?

    Câu trả lời

    repolarization

  577. Thẻ 577

    Câu hỏi

    Which term describes a communication junction between cells?

    Câu trả lời

    a synapse

  578. Thẻ 578

    Câu hỏi

    What is a neurotransmitter?

    Câu trả lời

    A chemical released by a neuron that changes the activity of a target cell.

  579. Thẻ 579

    Câu hỏi

    What is the refractory period?

    Câu trả lời

    A brief period after an action potential when another is impossible or requires a stronger stimulus.

  580. Thẻ 580

    Câu hỏi

    What is myelin?

    Câu trả lời

    An insulating sheath around some axons that speeds impulse conduction.

  581. Thẻ 581

    Câu hỏi

    What happens when membrane depolarization reaches threshold?

    Câu trả lời

    Voltage-gated channels trigger the self-amplifying events of an action potential.

  582. Thẻ 582

    Câu hỏi

    Which term describes a neuron-released signaling chemical?

    Câu trả lời

    a neurotransmitter

  583. Thẻ 583

    Câu hỏi

    Which term describes the recovery interval after an action potential?

    Câu trả lời

    the refractory period

  584. Thẻ 584

    Câu hỏi

    Which term describes the insulating axon sheath?

    Câu trả lời

    myelin

  585. Thẻ 585

    Câu hỏi

    What does the all-or-none principle mean for an action potential?

    Câu trả lời

    Once threshold is reached, the action potential has a characteristic size; stronger stimuli increase frequency, not its amplitude.

  586. Thẻ 586

    Câu hỏi

    How does myelin increase conduction speed?

    Câu trả lời

    Depolarizing current travels rapidly beneath myelin and action potentials regenerate mainly at gaps in the sheath.

  587. Thẻ 587

    Câu hỏi

    What is the basic sequence at a chemical synapse?

    Câu trả lời

    An impulse triggers neurotransmitter release; it diffuses across the cleft, binds receptors, and alters the postsynaptic cell.

  588. Thẻ 588

    Câu hỏi

    Why can a reflex response be rapid?

    Câu trả lời

    A short neural pathway produces an automatic response without waiting for conscious processing.

  589. Thẻ 589

    Câu hỏi

    What is sensory transduction?

    Câu trả lời

    Conversion of a physical or chemical stimulus into an electrical signal in a receptor cell.

  590. Thẻ 590

    Câu hỏi

    How does an action potential propagate along an axon?

    Câu trả lời

    Local current depolarizes the next membrane region to threshold, opening voltage-gated channels there.

  591. Thẻ 591

    Câu hỏi

    Why does an action potential normally travel in one direction along an axon?

    Câu trả lời

    The membrane just behind it is refractory and cannot immediately fire again.

  592. Thẻ 592

    Câu hỏi

    How is neurotransmitter action ended?

    Câu trả lời

    The transmitter is removed by enzymatic breakdown, reuptake, or diffusion away.

  593. Thẻ 593

    Câu hỏi

    What is sensory adaptation?

    Câu trả lời

    Reduced receptor or neural response during a constant, unchanging stimulus.

  594. Thẻ 594

    Câu hỏi

    How can a drug alter synaptic transmission?

    Câu trả lời

    It may mimic or block a transmitter, change its release, or change its removal from the synaptic cleft.

  595. Thẻ 595

    Câu hỏi

    What is an organ system?

    Câu trả lời

    A group of organs coordinating to perform major functions for an organism.

  596. Thẻ 596

    Câu hỏi

    What is a hormone?

    Câu trả lời

    A signaling molecule released into transport fluid and acting on target cells with suitable receptors.

  597. Thẻ 597

    Câu hỏi

    What is an endocrine gland?

    Câu trả lời

    A gland that secretes hormones into extracellular fluid and blood rather than through a duct.

  598. Thẻ 598

    Câu hỏi

    What is a hormone target cell?

    Câu trả lời

    A cell able to respond because it has the appropriate receptor.

  599. Thẻ 599

    Câu hỏi

    Which term describes a coordinated group of organs?

    Câu trả lời

    an organ system

  600. Thẻ 600

    Câu hỏi

    Which term describes a long-distance chemical messenger carried in body fluid?

    Câu trả lời

    a hormone

  601. Thẻ 601

    Câu hỏi

    Which term describes a ductless hormone-secreting gland?

    Câu trả lời

    an endocrine gland

  602. Thẻ 602

    Câu hỏi

    Which term describes a cell with a receptor for a particular hormone?

    Câu trả lời

    a hormone target cell

  603. Thẻ 603

    Câu hỏi

    What is digestion?

    Câu trả lời

    Mechanical and chemical breakdown of food into molecules small enough to absorb.

  604. Thẻ 604

    Câu hỏi

    What is absorption?

    Câu trả lời

    Movement of digested nutrients across an exchange surface into blood or lymph.

  605. Thẻ 605

    Câu hỏi

    What is peristalsis?

    Câu trả lời

    Coordinated waves of smooth-muscle contraction that move material through the digestive tract.

  606. Thẻ 606

    Câu hỏi

    What is an intestinal villus?

    Câu trả lời

    A finger-like projection increasing the absorptive surface of the small intestine.

  607. Thẻ 607

    Câu hỏi

    Which term describes breakdown of food into absorbable molecules?

    Câu trả lời

    digestion

  608. Thẻ 608

    Câu hỏi

    Which term describes movement of digested nutrients into transport fluids?

    Câu trả lời

    absorption

  609. Thẻ 609

    Câu hỏi

    Which term describes wave-like gut contractions moving contents?

    Câu trả lời

    peristalsis

  610. Thẻ 610

    Câu hỏi

    Which term describes a finger-like intestinal absorption projection?

    Câu trả lời

    an intestinal villus

  611. Thẻ 611

    Câu hỏi

    What is excretion?

    Câu trả lời

    Removal of metabolic waste products from the body.

  612. Thẻ 612

    Câu hỏi

    What is a nephron?

    Câu trả lời

    The microscopic functional unit of the kidney that filters blood and modifies filtrate into urine.

  613. Thẻ 613

    Câu hỏi

    What is ultrafiltration?

    Câu trả lời

    Pressure-driven filtration of small molecules from blood into a kidney capsule while cells and most proteins remain in blood.

  614. Thẻ 614

    Câu hỏi

    What is selective reabsorption?

    Câu trả lời

    Recovery of useful substances and regulated amounts of water and ions from kidney filtrate into blood.

  615. Thẻ 615

    Câu hỏi

    Which term describes removal of metabolic wastes?

    Câu trả lời

    excretion

  616. Thẻ 616

    Câu hỏi

    Which term describes the kidney's microscopic functional unit?

    Câu trả lời

    a nephron

  617. Thẻ 617

    Câu hỏi

    Which term describes pressure filtration at the start of a nephron?

    Câu trả lời

    ultrafiltration

  618. Thẻ 618

    Câu hỏi

    Which term describes return of useful substances from kidney filtrate to blood?

    Câu trả lời

    selective reabsorption

  619. Thẻ 619

    Câu hỏi

    What is skeletal muscle?

    Câu trả lời

    Striated voluntary muscle attached to the skeleton and used for movement and posture.

  620. Thẻ 620

    Câu hỏi

    What is an antagonistic muscle pair?

    Câu trả lời

    Two muscles producing opposite movements at a joint because muscles pull but do not push.

  621. Thẻ 621

    Câu hỏi

    How do nervous and endocrine signaling generally differ?

    Câu trả lời

    Neural signals are rapid and targeted; hormonal signals are usually slower, longer-lasting, and distributed through body fluids.

  622. Thẻ 622

    Câu hỏi

    Why does a circulating hormone affect only some cells?

    Câu trả lời

    Only target cells express receptors that recognize the hormone and activate a response.

  623. Thẻ 623

    Câu hỏi

    Which term describes voluntary striated muscle that moves the skeleton?

    Câu trả lời

    skeletal muscle

  624. Thẻ 624

    Câu hỏi

    Which term describes two muscles producing opposite joint movements?

    Câu trả lời

    an antagonistic muscle pair

  625. Thẻ 625

    Câu hỏi

    What is the final absorbable product of most dietary carbohydrate digestion?

    Câu trả lời

    Monosaccharides, especially glucose.

  626. Thẻ 626

    Câu hỏi

    What are the main absorbable products of protein digestion?

    Câu trả lời

    Amino acids and small peptides that are completed to amino acids during absorption.

  627. Thẻ 627

    Câu hỏi

    How is the small intestine adapted for absorption?

    Câu trả lời

    Folds, villi, and microvilli increase area; a thin epithelium, rich blood supply, and lymph vessels support transport.

  628. Thẻ 628

    Câu hỏi

    Name three integrative roles of the liver.

    Câu trả lời

    It processes absorbed nutrients, regulates blood chemistry, detoxifies substances, produces bile, and converts ammonia to urea; any three are sufficient.

  629. Thẻ 629

    Câu hỏi

    Why are blood cells and most plasma proteins absent from normal kidney filtrate?

    Câu trả lời

    They are too large to cross the filtration barrier.

  630. Thẻ 630

    Câu hỏi

    How do muscles move a bone at a joint?

    Câu trả lời

    Contraction shortens the muscle, pulling through a tendon on the bone.

  631. Thẻ 631

    Câu hỏi

    Why are antagonistic muscles needed at many joints?

    Câu trả lời

    A muscle can pull in one direction but cannot push itself back, so an opposing muscle produces the reverse movement.

  632. Thẻ 632

    Câu hỏi

    Why must organ systems be integrated rather than acting independently?

    Câu trả lời

    Each system depends on materials, signals, waste removal, and stable conditions supplied by other systems.

  633. Thẻ 633

    Câu hỏi

    Why do many absorbed lipids enter lymph before blood?

    Câu trả lời

    Intestinal cells package them into lipoprotein particles too large to enter ordinary blood capillaries directly.

  634. Thẻ 634

    Câu hỏi

    Why is glucose normally absent from final urine?

    Câu trả lời

    Filtered glucose is selectively reabsorbed into blood when transporter capacity is not exceeded.

  635. Thẻ 635

    Câu hỏi

    How do respiratory, circulatory, and muscular systems cooperate during exercise?

    Câu trả lời

    Ventilation supplies oxygen, circulation transports gases and fuels, and muscles use ATP while returning carbon dioxide, heat, and metabolites.

  636. Thẻ 636

    Câu hỏi

    How do liver, circulation, and kidneys cooperate in nitrogen-waste removal?

    Câu trả lời

    The liver converts toxic ammonia to urea, blood carries urea, and kidneys filter and excrete it.

  637. Thẻ 637

    Câu hỏi

    What is a pathogen?

    Câu trả lời

    A biological agent capable of causing disease.

  638. Thẻ 638

    Câu hỏi

    What is an antigen?

    Câu trả lời

    A molecule recognized specifically by an antibody or lymphocyte receptor.

  639. Thẻ 639

    Câu hỏi

    What is innate immunity?

    Câu trả lời

    Rapid, nonspecific defense mechanisms present without prior exposure.

  640. Thẻ 640

    Câu hỏi

    What is adaptive immunity?

    Câu trả lời

    Specific defense that develops through lymphocyte activation and can form memory.

  641. Thẻ 641

    Câu hỏi

    Which term describes a disease-causing biological agent?

    Câu trả lời

    a pathogen

  642. Thẻ 642

    Câu hỏi

    Which term describes a molecule specifically recognized by adaptive immune receptors?

    Câu trả lời

    an antigen

  643. Thẻ 643

    Câu hỏi

    Which term describes rapid nonspecific immune defense?

    Câu trả lời

    innate immunity

  644. Thẻ 644

    Câu hỏi

    Which term describes specific immune defense capable of memory?

    Câu trả lời

    adaptive immunity

  645. Thẻ 645

    Câu hỏi

    What is a phagocyte?

    Câu trả lời

    A cell that engulfs and digests microbes, particles, or damaged cells.

  646. Thẻ 646

    Câu hỏi

    What is a lymphocyte?

    Câu trả lời

    An adaptive immune cell with receptors specific to particular antigens.

  647. Thẻ 647

    Câu hỏi

    What is an antibody?

    Câu trả lời

    A secreted immunoglobulin that binds a specific antigen.

  648. Thẻ 648

    Câu hỏi

    What is a B lymphocyte?

    Câu trả lời

    A lymphocyte that can differentiate into antibody-secreting plasma cells and memory cells.

  649. Thẻ 649

    Câu hỏi

    Which term describes an engulfing immune cell?

    Câu trả lời

    a phagocyte

  650. Thẻ 650

    Câu hỏi

    Which term describes an antigen-specific adaptive immune cell?

    Câu trả lời

    a lymphocyte

  651. Thẻ 651

    Câu hỏi

    Which term describes a secreted antigen-binding immunoglobulin?

    Câu trả lời

    an antibody

  652. Thẻ 652

    Câu hỏi

    Which term describes the lymphocyte lineage that produces antibody-secreting cells?

    Câu trả lời

    a B lymphocyte

  653. Thẻ 653

    Câu hỏi

    What is a helper T cell?

    Câu trả lời

    A lymphocyte that coordinates immune responses through contact signals and cytokines.

  654. Thẻ 654

    Câu hỏi

    What is an immune memory cell?

    Câu trả lời

    A long-lived lymphocyte that responds rapidly after re-exposure to its antigen.

  655. Thẻ 655

    Câu hỏi

    What is vaccination?

    Câu trả lời

    Deliberate exposure to a safe form or component of an antigen to generate protective immune memory.

  656. Thẻ 656

    Câu hỏi

    What is an antibiotic?

    Câu trả lời

    A substance that kills bacteria or inhibits their growth at clinically useful doses.

  657. Thẻ 657

    Câu hỏi

    Which term describes the T cell that coordinates other immune cells?

    Câu trả lời

    a helper T cell

  658. Thẻ 658

    Câu hỏi

    Which term describes a long-lived lymphocyte enabling faster re-exposure response?

    Câu trả lời

    an immune memory cell

  659. Thẻ 659

    Câu hỏi

    Which term describes safe antigen exposure used to create immune memory?

    Câu trả lời

    vaccination

  660. Thẻ 660

    Câu hỏi

    Which term describes a drug acting against bacteria?

    Câu trả lời

    an antibiotic

  661. Thẻ 661

    Câu hỏi

    What are examples of first-line defenses against pathogens?

    Câu trả lời

    Intact skin, mucus, cilia, antimicrobial secretions, stomach acidity, and competing microbiota.

  662. Thẻ 662

    Câu hỏi

    How does inflammation help defend damaged tissue?

    Câu trả lời

    It increases local blood flow and vessel permeability and recruits immune cells and defensive molecules.

  663. Thẻ 663

    Câu hỏi

    What happens during phagocytosis?

    Câu trả lời

    A cell surrounds a particle in a vesicle, then fuses it with digestive compartments to destroy or process it.

  664. Thẻ 664

    Câu hỏi

    How can antibodies help eliminate a pathogen?

    Câu trả lời

    They can neutralize targets, block attachment, clump particles, and mark them for phagocytosis or complement attack.

  665. Thẻ 665

    Câu hỏi

    Why can a vaccine generate protection without causing the full disease?

    Câu trả lời

    It presents antigen in a weakened, inactivated, partial, or encoded form that stimulates immunity with much lower risk.

  666. Thẻ 666

    Câu hỏi

    Why do antibiotics not treat viral infections?

    Câu trả lời

    Viruses lack the bacterial structures and independent metabolic processes targeted by antibiotics.

  667. Thẻ 667

    Câu hỏi

    What determines the antigen specificity of a lymphocyte?

    Câu trả lời

    The molecular shape and chemistry of its unique surface receptor.

  668. Thẻ 668

    Câu hỏi

    What is clonal selection?

    Câu trả lời

    An antigen activates lymphocytes with matching receptors, causing them to proliferate and differentiate.

  669. Thẻ 669

    Câu hỏi

    Why is a secondary adaptive immune response usually faster and stronger?

    Câu trả lời

    Memory cells are more numerous and activate rapidly, producing effective cells and antibodies sooner.

  670. Thẻ 670

    Câu hỏi

    How can high vaccination coverage protect some unvaccinated people?

    Câu trả lời

    Reduced transmission makes encounters with infectious individuals less likely, though protection is incomplete and pathogen-dependent.

  671. Thẻ 671

    Câu hỏi

    How does antibiotic use select for resistant bacteria?

    Câu trả lời

    Susceptible bacteria are removed while resistant variants survive and reproduce, increasing resistance-allele frequency.

  672. Thẻ 672

    Câu hỏi

    Why can unnecessary or incomplete antibiotic exposure promote resistance?

    Câu trả lời

    It creates selection favoring resistant cells while potentially leaving surviving bacteria to multiply and spread.

  673. Thẻ 673

    Câu hỏi

    What is an allergy?

    Câu trả lời

    An immune response to a normally harmless antigen that causes tissue symptoms or damage.

  674. Thẻ 674

    Câu hỏi

    What is asexual reproduction?

    Câu trả lời

    Production of offspring from one parent without fusion of gametes.

  675. Thẻ 675

    Câu hỏi

    What is sexual reproduction?

    Câu trả lời

    Production of offspring involving fusion of haploid gametes.

  676. Thẻ 676

    Câu hỏi

    What is a gamete?

    Câu trả lời

    A haploid reproductive cell able to fuse with another gamete.

  677. Thẻ 677

    Câu hỏi

    What is fertilization?

    Câu trả lời

    Fusion of gamete nuclei to form a diploid zygote.

  678. Thẻ 678

    Câu hỏi

    Which term describes reproduction without gamete fusion?

    Câu trả lời

    asexual reproduction

  679. Thẻ 679

    Câu hỏi

    Which term describes reproduction involving gamete fusion?

    Câu trả lời

    sexual reproduction

  680. Thẻ 680

    Câu hỏi

    Which term describes a haploid reproductive cell?

    Câu trả lời

    a gamete

  681. Thẻ 681

    Câu hỏi

    Which term describes fusion of gamete nuclei?

    Câu trả lời

    fertilization

  682. Thẻ 682

    Câu hỏi

    What is a zygote?

    Câu trả lời

    The diploid cell formed by fertilization.

  683. Thẻ 683

    Câu hỏi

    What is meiosis?

    Câu trả lời

    Cell division that halves chromosome number and usually produces genetically varied haploid cells.

  684. Thẻ 684

    Câu hỏi

    What is ovulation?

    Câu trả lời

    Release of a secondary oocyte from an ovary.

  685. Thẻ 685

    Câu hỏi

    What is implantation?

    Câu trả lời

    Attachment and embedding of an early embryo in the uterine lining.

  686. Thẻ 686

    Câu hỏi

    Which term describes the first diploid cell after fertilization?

    Câu trả lời

    a zygote

  687. Thẻ 687

    Câu hỏi

    Which term describes division producing varied haploid cells?

    Câu trả lời

    meiosis

  688. Thẻ 688

    Câu hỏi

    Which term describes release of an oocyte from an ovary?

    Câu trả lời

    ovulation

  689. Thẻ 689

    Câu hỏi

    Which term describes embedding of an early embryo in the uterine lining?

    Câu trả lời

    implantation

  690. Thẻ 690

    Câu hỏi

    What is the placenta?

    Câu trả lời

    A temporary organ that exchanges materials between maternal and fetal blood supplies without normally mixing them directly.

  691. Thẻ 691

    Câu hỏi

    What is pollination?

    Câu trả lời

    Transfer of pollen from an anther to a receptive stigma.

  692. Thẻ 692

    Câu hỏi

    Why does sexual reproduction usually produce more genetic variation than asexual reproduction?

    Câu trả lời

    Meiosis reshuffles alleles and random fertilization combines genomes from two gametes.

  693. Thẻ 693

    Câu hỏi

    Why must gametes be haploid?

    Câu trả lời

    Fusion of two haploid gametes restores the diploid chromosome number instead of doubling it each generation.

  694. Thẻ 694

    Câu hỏi

    Which term describes the maternal-fetal exchange organ?

    Câu trả lời

    the placenta

  695. Thẻ 695

    Câu hỏi

    Which term describes transfer of pollen to a stigma?

    Câu trả lời

    pollination

  696. Thẻ 696

    Câu hỏi

    What are major roles of FSH in the ovarian cycle?

    Câu trả lời

    It stimulates follicle development and supports estrogen secretion.

  697. Thẻ 697

    Câu hỏi

    What is a major role of the mid-cycle LH surge?

    Câu trả lời

    It triggers ovulation and formation of the corpus luteum.

  698. Thẻ 698

    Câu hỏi

    How does estrogen contribute to the uterine cycle?

    Câu trả lời

    It promotes repair and thickening of the uterine lining after menstruation.

  699. Thẻ 699

    Câu hỏi

    How does progesterone contribute to the uterine cycle?

    Câu trả lời

    It maintains a thick, secretory uterine lining after ovulation.

  700. Thẻ 700

    Câu hỏi

    Where does human fertilization usually occur?

    Câu trả lời

    In an oviduct, before the early embryo reaches the uterus.

  701. Thẻ 701

    Câu hỏi

    What happens after compatible pollen reaches a flower's stigma?

    Câu trả lời

    A pollen tube grows toward an ovule and delivers male nuclei for fertilization.

  702. Thẻ 702

    Câu hỏi

    Why does menstruation usually begin if pregnancy does not occur?

    Câu trả lời

    The corpus luteum degenerates, progesterone and estrogen fall, and the uterine lining is no longer maintained.

  703. Thẻ 703

    Câu hỏi

    What substances commonly cross the placenta between mother and fetus?

    Câu trả lời

    Oxygen and nutrients move toward the fetus; carbon dioxide and nitrogenous wastes move toward the mother.

  704. Thẻ 704

    Câu hỏi

    How can contraception prevent pregnancy in different ways?

    Câu trả lời

    Methods can inhibit ovulation, block sperm from reaching an egg, prevent fertilization, or permanently interrupt the reproductive ducts.

  705. Thẻ 705

    Câu hỏi

    What is homeostasis?

    Câu trả lời

    Maintenance of internal conditions within ranges compatible with normal function despite change.

  706. Thẻ 706

    Câu hỏi

    What is negative feedback?

    Câu trả lời

    Control in which a deviation triggers responses that oppose the original change.

  707. Thẻ 707

    Câu hỏi

    What is a set point?

    Câu trả lời

    The target value or range around which a regulated variable is maintained.

  708. Thẻ 708

    Câu hỏi

    What is a homeostatic receptor?

    Câu trả lời

    A sensor that detects a change in a regulated variable.

  709. Thẻ 709

    Câu hỏi

    Which term describes maintenance of a stable functional internal environment?

    Câu trả lời

    homeostasis

  710. Thẻ 710

    Câu hỏi

    Which term describes feedback that counteracts a deviation?

    Câu trả lời

    negative feedback

  711. Thẻ 711

    Câu hỏi

    Which term describes the target around which a variable is regulated?

    Câu trả lời

    a set point

  712. Thẻ 712

    Câu hỏi

    Which term describes the sensor in a feedback system?

    Câu trả lời

    a homeostatic receptor

  713. Thẻ 713

    Câu hỏi

    What is a control center?

    Câu trả lời

    The component that compares information with a target and coordinates a response.

  714. Thẻ 714

    Câu hỏi

    What is an effector?

    Câu trả lời

    A muscle, gland, or other component that carries out a control response.

  715. Thẻ 715

    Câu hỏi

    What is thermoregulation?

    Câu trả lời

    Control of body temperature within a functional range.

  716. Thẻ 716

    Câu hỏi

    What is vasodilation?

    Câu trả lời

    Widening of blood vessels, often increasing blood flow near the skin.

  717. Thẻ 717

    Câu hỏi

    Which term describes the feedback component that evaluates input and directs a response?

    Câu trả lời

    a control center

  718. Thẻ 718

    Câu hỏi

    Which term describes the component that executes a physiological response?

    Câu trả lời

    an effector

  719. Thẻ 719

    Câu hỏi

    Which term describes physiological regulation of body temperature?

    Câu trả lời

    thermoregulation

  720. Thẻ 720

    Câu hỏi

    Which term describes widening of blood vessels?

    Câu trả lời

    vasodilation

  721. Thẻ 721

    Câu hỏi

    What is vasoconstriction?

    Câu trả lời

    Narrowing of blood vessels, often reducing blood flow near the skin.

  722. Thẻ 722

    Câu hỏi

    What is insulin?

    Câu trả lời

    A pancreatic hormone that lowers elevated blood glucose by promoting uptake and storage.

  723. Thẻ 723

    Câu hỏi

    What is glucagon?

    Câu trả lời

    A pancreatic hormone that raises low blood glucose by promoting release of stored fuel.

  724. Thẻ 724

    Câu hỏi

    What are the main components of a homeostatic feedback loop?

    Câu trả lời

    A regulated variable, receptor, control center, effectors, and responses that alter the variable.

  725. Thẻ 725

    Câu hỏi

    Which term describes narrowing of blood vessels?

    Câu trả lời

    vasoconstriction

  726. Thẻ 726

    Câu hỏi

    Which term describes the pancreatic hormone that lowers blood glucose?

    Câu trả lời

    insulin

  727. Thẻ 727

    Câu hỏi

    Which term describes the pancreatic hormone that raises blood glucose?

    Câu trả lời

    glucagon

  728. Thẻ 728

    Câu hỏi

    What happens when blood glucose rises after a meal?

    Câu trả lời

    Insulin secretion increases, promoting glucose uptake and storage so blood glucose falls toward its normal range.

  729. Thẻ 729

    Câu hỏi

    What happens when blood glucose falls during fasting?

    Câu trả lời

    Glucagon secretion increases, promoting glycogen breakdown and glucose release by the liver.

  730. Thẻ 730

    Câu hỏi

    How does sweating cool the body?

    Câu trả lời

    Evaporation of water from skin transfers heat to the environment.

  731. Thẻ 731

    Câu hỏi

    How does skin vasodilation increase heat loss?

    Câu trả lời

    It brings more warm blood near the surface, increasing transfer of heat to the environment.

  732. Thẻ 732

    Câu hỏi

    How does shivering warm the body?

    Câu trả lời

    Rapid involuntary muscle contractions increase respiration and heat production.

  733. Thẻ 733

    Câu hỏi

    Does homeostasis keep internal conditions perfectly constant?

    Câu trả lời

    No. Variables fluctuate within controlled ranges around target values.

  734. Thẻ 734

    Câu hỏi

    How does ADH help conserve water?

    Câu trả lời

    It increases water permeability in kidney collecting ducts, so more water is reabsorbed and urine becomes more concentrated.

  735. Thẻ 735

    Câu hỏi

    How should ADH secretion change during dehydration?

    Câu trả lời

    It should increase, promoting greater water reabsorption by the kidneys.

  736. Thẻ 736

    Câu hỏi

    How does positive feedback differ from negative feedback?

    Câu trả lời

    Positive feedback amplifies a change until an endpoint; negative feedback opposes a change and stabilizes a variable.

  737. Thẻ 737

    Câu hỏi

    Why can diabetes mellitus cause persistently high blood glucose?

    Câu trả lời

    Insulin production may be insufficient or target cells may respond poorly to insulin.

  738. Thẻ 738

    Câu hỏi

    What is biological evolution?

    Câu trả lời

    Change in heritable characteristics or allele frequencies of a population across generations.

  739. Thẻ 739

    Câu hỏi

    What is allele frequency?

    Câu trả lời

    The proportion of gene copies in a population represented by a particular allele.

  740. Thẻ 740

    Câu hỏi

    What is microevolution?

    Câu trả lời

    Evolutionary change in allele frequencies within populations over relatively short timescales.

  741. Thẻ 741

    Câu hỏi

    What is speciation?

    Câu trả lời

    Evolutionary formation of new species.

  742. Thẻ 742

    Câu hỏi

    Which term describes change in a population's heritable composition across generations?

    Câu trả lời

    biological evolution

  743. Thẻ 743

    Câu hỏi

    Which term describes the proportion of a population's gene copies that are one allele?

    Câu trả lời

    allele frequency

  744. Thẻ 744

    Câu hỏi

    Which term describes short-timescale allele-frequency change within populations?

    Câu trả lời

    microevolution

  745. Thẻ 745

    Câu hỏi

    Which term describes formation of new species?

    Câu trả lời

    speciation

  746. Thẻ 746

    Câu hỏi

    What is reproductive isolation?

    Câu trả lời

    Barriers that prevent or greatly reduce gene flow between populations.

  747. Thẻ 747

    Câu hỏi

    What is allopatric speciation?

    Câu trả lời

    Speciation after populations become geographically separated and diverge.

  748. Thẻ 748

    Câu hỏi

    What is sympatric speciation?

    Câu trả lời

    Speciation without geographic separation, through reproductive isolation within the same area.

  749. Thẻ 749

    Câu hỏi

    What are homologous structures?

    Câu trả lời

    Structures similar because they were inherited from a common ancestor, even if their functions differ.

  750. Thẻ 750

    Câu hỏi

    Which term describes barriers reducing gene flow between populations?

    Câu trả lời

    reproductive isolation

  751. Thẻ 751

    Câu hỏi

    Which term describes speciation following geographic separation?

    Câu trả lời

    allopatric speciation

  752. Thẻ 752

    Câu hỏi

    Which term describes speciation within the same geographic area?

    Câu trả lời

    sympatric speciation

  753. Thẻ 753

    Câu hỏi

    Which term describes structures similar through common ancestry?

    Câu trả lời

    homologous structures

  754. Thẻ 754

    Câu hỏi

    What are analogous structures?

    Câu trả lời

    Structures with similar functions that evolved independently rather than from the same ancestral structure.

  755. Thẻ 755

    Câu hỏi

    What is a common ancestor?

    Câu trả lời

    An ancestral population from which two or more descendant lineages evolved.

  756. Thẻ 756

    Câu hỏi

    How does the fossil record provide evidence for evolution?

    Câu trả lời

    It documents organisms from different times, including appearance, change, persistence, and extinction of lineages.

  757. Thẻ 757

    Câu hỏi

    How do DNA and protein sequences provide evidence of common ancestry?

    Câu trả lời

    Shared sequences are inherited; greater similarity generally indicates more recent common ancestry.

  758. Thẻ 758

    Câu hỏi

    Which term describes functionally similar structures of independent evolutionary origin?

    Câu trả lời

    analogous structures

  759. Thẻ 759

    Câu hỏi

    Which term describes an ancestral population shared by descendant lineages?

    Câu trả lời

    a common ancestor

  760. Thẻ 760

    Câu hỏi

    What is the evolutionary significance of extinction?

    Câu trả lời

    It permanently ends a lineage and can alter ecological opportunities and the future diversification of survivors.

  761. Thẻ 761

    Câu hỏi

    Do individual organisms evolve during their lifetimes?

    Câu trả lời

    No. Individuals develop and acclimate; evolution is heritable change in populations across generations.

  762. Thẻ 762

    Câu hỏi

    Why is evolution represented as a branching tree rather than a ladder?

    Câu trả lời

    Lineages split from common ancestors; living species are not arranged as stages toward a single goal.

  763. Thẻ 763

    Câu hỏi

    How can island species support evolutionary explanations?

    Câu trả lời

    Their similarities to nearby mainland ancestors and unique local adaptations fit divergence after colonization and isolation.

  764. Thẻ 764

    Câu hỏi

    How can geographic isolation lead to reproductive isolation?

    Câu trả lời

    Separated populations accumulate different mutations and experience different selection and drift until interbreeding is reduced.

  765. Thẻ 765

    Câu hỏi

    Why can continuing gene flow slow speciation?

    Câu trả lời

    Movement of alleles between populations counteracts genetic divergence.

  766. Thẻ 766

    Câu hỏi

    Why can unrelated species evolve similar traits?

    Câu trả lời

    Similar environmental challenges can favor similar functional solutions through convergent evolution.

  767. Thẻ 767

    Câu hỏi

    Which parts of evolution are random and which are nonrandom?

    Câu trả lời

    Mutation and many sampling effects are random with respect to need; natural selection nonrandomly favors variants that reproduce better in a given environment.

  768. Thẻ 768

    Câu hỏi

    What is conservation biology?

    Câu trả lời

    The science and practice of protecting biodiversity, ecological processes, and evolutionary potential.

  769. Thẻ 769

    Câu hỏi

    What is habitat fragmentation?

    Câu trả lời

    Division of continuous habitat into smaller, isolated patches.

  770. Thẻ 770

    Câu hỏi

    What is an endangered species?

    Câu trả lời

    A species facing a high risk of extinction in the wild.

  771. Thẻ 771

    Câu hỏi

    What is in situ conservation?

    Câu trả lời

    Protection of species in their natural habitats and ecological communities.

  772. Thẻ 772

    Câu hỏi

    Which term describes the protection of biodiversity and ecological processes?

    Câu trả lời

    conservation biology

  773. Thẻ 773

    Câu hỏi

    Which term describes division of habitat into isolated patches?

    Câu trả lời

    habitat fragmentation

  774. Thẻ 774

    Câu hỏi

    Which term describes a species at high risk of extinction?

    Câu trả lời

    an endangered species

  775. Thẻ 775

    Câu hỏi

    Which term describes conservation within natural habitat?

    Câu trả lời

    in situ conservation

  776. Thẻ 776

    Câu hỏi

    What is ex situ conservation?

    Câu trả lời

    Protection of organisms or genetic material outside the natural habitat.

  777. Thẻ 777

    Câu hỏi

    What is a population bottleneck?

    Câu trả lời

    A sharp population reduction that can remove genetic variation by chance.

  778. Thẻ 778

    Câu hỏi

    What is a wildlife corridor?

    Câu trả lời

    Habitat connecting isolated patches to permit movement and gene flow.

  779. Thẻ 779

    Câu hỏi

    What major human-driven processes threaten biodiversity?

    Câu trả lời

    Habitat loss, overexploitation, invasive species, pollution, and climate change.

  780. Thẻ 780

    Câu hỏi

    Which term describes conservation outside natural habitat?

    Câu trả lời

    ex situ conservation

  781. Thẻ 781

    Câu hỏi

    Which term describes a severe population reduction that loses genetic diversity?

    Câu trả lời

    a population bottleneck

  782. Thẻ 782

    Câu hỏi

    Which term describes habitat linking isolated populations?

    Câu trả lời

    a wildlife corridor

  783. Thẻ 783

    Câu hỏi

    What makes a protected area more effective than a boundary alone?

    Câu trả lời

    Adequate size, representative habitat, enforcement, connectivity, local support, and management of external threats.

  784. Thẻ 784

    Câu hỏi

    Why is long-term population monitoring important in conservation?

    Câu trả lời

    It reveals trends, tests whether management works, and provides early warning of decline.

  785. Thẻ 785

    Câu hỏi

    How can ecosystem services support the case for conservation?

    Câu trả lời

    Healthy ecosystems provide benefits such as pollination, water purification, carbon storage, soil formation, and cultural value.

  786. Thẻ 786

    Câu hỏi

    Why are very small populations especially vulnerable to extinction?

    Câu trả lời

    Chance events, inbreeding, low genetic diversity, and difficulty finding mates can reinforce decline.

  787. Thẻ 787

    Câu hỏi

    What are benefits and limits of captive-breeding programs?

    Câu trả lời

    They can prevent immediate extinction and manage breeding, but may lose diversity, alter behavior, and fail without safe habitat for release.

  788. Thẻ 788

    Câu hỏi

    Why can controlling an invasive species aid conservation?

    Câu trả lời

    It can reduce predation, competition, disease, or habitat alteration affecting native species.

  789. Thẻ 789

    Câu hỏi

    Why must conservation priorities consider more than species count?

    Câu trả lời

    Endemism, evolutionary distinctness, ecological roles, threat severity, feasibility, and human needs also matter.

  790. Thẻ 790

    Câu hỏi

    What is an adaptation?

    Câu trả lời

    A heritable characteristic that increases reproductive success in a particular environment.

  791. Thẻ 791

    Câu hỏi

    What is acclimation?

    Câu trả lời

    A reversible physiological or behavioral adjustment by an individual to environmental change.

  792. Thẻ 792

    Câu hỏi

    What is a structural adaptation?

    Câu trả lời

    An inherited anatomical feature that improves performance in an environment.

  793. Thẻ 793

    Câu hỏi

    What is a physiological adaptation?

    Câu trả lời

    An inherited functional or biochemical feature that improves performance in an environment.

  794. Thẻ 794

    Câu hỏi

    Which term describes a heritable trait improving reproductive success in context?

    Câu trả lời

    an adaptation

  795. Thẻ 795

    Câu hỏi

    Which term describes an individual's reversible adjustment to environmental change?

    Câu trả lời

    acclimation

  796. Thẻ 796

    Câu hỏi

    Which term describes an adaptive anatomical feature?

    Câu trả lời

    a structural adaptation

  797. Thẻ 797

    Câu hỏi

    Which term describes an adaptive functional or biochemical feature?

    Câu trả lời

    a physiological adaptation

  798. Thẻ 798

    Câu hỏi

    What is a behavioral adaptation?

    Câu trả lời

    An inherited behavior pattern that improves survival or reproduction.

  799. Thẻ 799

    Câu hỏi

    What is an environmental tolerance range?

    Câu trả lời

    The range of an abiotic condition within which an organism can survive and reproduce.

  800. Thẻ 800

    Câu hỏi

    What is evolutionary fitness?

    Câu trả lời

    Relative contribution of an individual or genotype to future generations.

  801. Thẻ 801

    Câu hỏi

    How can a thick cuticle and reduced leaves help a desert plant?

    Câu trả lời

    The cuticle lowers surface permeability, while smaller leaves reduce the area from which water can evaporate.

  802. Thẻ 802

    Câu hỏi

    Which term describes an adaptive behavior pattern?

    Câu trả lời

    a behavioral adaptation

  803. Thẻ 803

    Câu hỏi

    Which term describes the survivable range of an abiotic condition?

    Câu trả lời

    an environmental tolerance range

  804. Thẻ 804

    Câu hỏi

    Which term describes relative reproductive contribution to future generations?

    Câu trả lời

    evolutionary fitness

  805. Thẻ 805

    Câu hỏi

    How can a streamlined body adapt an aquatic animal to movement?

    Câu trả lời

    It reduces drag, lowering the energy needed to move through water.

  806. Thẻ 806

    Câu hỏi

    Does an organism develop an adaptation because it needs one?

    Câu trả lời

    No. Heritable variants arise without regard to need, and selection changes their frequencies across generations.

  807. Thẻ 807

    Câu hỏi

    Why may organisms from different thermal environments have enzymes with different temperature optima?

    Câu trả lời

    Selection favors protein structures that balance flexibility and stability under local temperatures.

  808. Thẻ 808

    Câu hỏi

    Why is an adaptation rarely beneficial in every environment?

    Câu trả lời

    Traits carry costs and their advantage depends on local resources, competitors, predators, and physical conditions.

  809. Thẻ 809

    Câu hỏi

    How does phenotypic plasticity differ from genetic adaptation?

    Câu trả lời

    Plasticity lets one genotype produce different phenotypes; adaptation is a heritable population trait shaped across generations.

  810. Thẻ 810

    Câu hỏi

    What is local adaptation?

    Câu trả lời

    A population has higher fitness in its home environment than foreign populations because selection favored local traits.

  811. Thẻ 811

    Câu hỏi

    What is an ecological niche?

    Câu trả lời

    The set of environmental conditions, resources, interactions, and functional roles associated with a species.

  812. Thẻ 812

    Câu hỏi

    What is a habitat?

    Câu trả lời

    The physical place or environment where an organism lives.

  813. Thẻ 813

    Câu hỏi

    What is a fundamental niche?

    Câu trả lời

    The full range of conditions and resources a species could use without limiting biotic interactions.

  814. Thẻ 814

    Câu hỏi

    What is a realized niche?

    Câu trả lời

    The conditions and resources a species actually uses after competition and other interactions.

  815. Thẻ 815

    Câu hỏi

    Which term describes a species' environmental requirements and ecological role?

    Câu trả lời

    an ecological niche

  816. Thẻ 816

    Câu hỏi

    Which term describes the place where an organism lives?

    Câu trả lời

    a habitat

  817. Thẻ 817

    Câu hỏi

    Which term describes the potential niche without limiting biotic interactions?

    Câu trả lời

    a fundamental niche

  818. Thẻ 818

    Câu hỏi

    Which term describes the niche actually occupied in nature?

    Câu trả lời

    a realized niche

  819. Thẻ 819

    Câu hỏi

    What is competition?

    Câu trả lời

    An interaction in which organisms reduce one another's access to a limited resource.

  820. Thẻ 820

    Câu hỏi

    What is mutualism?

    Câu trả lời

    An interaction in which both participating species benefit.

  821. Thẻ 821

    Câu hỏi

    What is predation?

    Câu trả lời

    An interaction in which one organism kills and consumes another.

  822. Thẻ 822

    Câu hỏi

    How does a habitat differ from a niche?

    Câu trả lời

    A habitat is where an organism lives; a niche includes how it uses conditions and resources and interacts there.

  823. Thẻ 823

    Câu hỏi

    Which term describes an interaction over a limited resource that harms both competitors?

    Câu trả lời

    competition

  824. Thẻ 824

    Câu hỏi

    Which term describes an interspecific interaction benefiting both partners?

    Câu trả lời

    mutualism

  825. Thẻ 825

    Câu hỏi

    Which term describes an interaction where one organism kills and eats another?

    Câu trả lời

    predation

  826. Thẻ 826

    Câu hỏi

    What kinds of factors define a niche?

    Câu trả lời

    Abiotic factors such as temperature and moisture, plus biotic factors such as food, competitors, predators, and partners.

  827. Thẻ 827

    Câu hỏi

    What does competitive exclusion predict?

    Câu trả lời

    Species with effectively identical niches cannot coexist indefinitely under stable conditions; one is excluded or niches diverge.

  828. Thẻ 828

    Câu hỏi

    How can resource partitioning reduce competition?

    Câu trả lời

    Species use different resources, places, or times, reducing niche overlap.

  829. Thẻ 829

    Câu hỏi

    What is a keystone species?

    Câu trả lời

    A species whose effect on community structure is disproportionately large relative to its abundance.

  830. Thẻ 830

    Câu hỏi

    Why can an introduced species expand rapidly in a new community?

    Câu trả lời

    It may encounter abundant resources, suitable climate, and fewer predators, pathogens, or competitors.

  831. Thẻ 831

    Câu hỏi

    Can an organism alter the niche conditions of other species?

    Câu trả lời

    Yes. Ecosystem engineers modify habitat structure or resource availability, changing opportunities for other organisms.

  832. Thẻ 832

    Câu hỏi

    What is a population?

    Câu trả lời

    Individuals of the same species living in the same area at the same time.

  833. Thẻ 833

    Câu hỏi

    What is an ecological community?

    Câu trả lời

    Populations of different species living and interacting in an area.

  834. Thẻ 834

    Câu hỏi

    What is an ecosystem?

    Câu trả lời

    A community together with its physical environment and their interactions.

  835. Thẻ 835

    Câu hỏi

    What is carrying capacity?

    Câu trả lời

    The population size an environment can sustain over time under given conditions.

  836. Thẻ 836

    Câu hỏi

    Which term describes same-species individuals sharing an area and time?

    Câu trả lời

    a population

  837. Thẻ 837

    Câu hỏi

    Which term describes interacting populations of different species?

    Câu trả lời

    an ecological community

  838. Thẻ 838

    Câu hỏi

    Which term describes a community plus its abiotic environment?

    Câu trả lời

    an ecosystem

  839. Thẻ 839

    Câu hỏi

    Which term describes the long-term supportable population size?

    Câu trả lời

    carrying capacity

  840. Thẻ 840

    Câu hỏi

    What is population density?

    Câu trả lời

    The number of individuals per unit area or volume.

  841. Thẻ 841

    Câu hỏi

    What is a limiting factor?

    Câu trả lời

    A resource or condition that restricts population growth or distribution.

  842. Thẻ 842

    Câu hỏi

    What is a density-dependent factor?

    Câu trả lời

    A factor whose effect strengthens as population density increases.

  843. Thẻ 843

    Câu hỏi

    What is a density-independent factor?

    Câu trả lời

    A factor whose effect is not primarily determined by population density.

  844. Thẻ 844

    Câu hỏi

    Which term describes individuals per unit area or volume?

    Câu trả lời

    population density

  845. Thẻ 845

    Câu hỏi

    Which term describes a resource or condition restricting a population?

    Câu trả lời

    a limiting factor

  846. Thẻ 846

    Câu hỏi

    Which term describes a factor with stronger effects at higher density?

    Câu trả lời

    a density-dependent factor

  847. Thẻ 847

    Câu hỏi

    Which term describes a factor acting largely regardless of population density?

    Câu trả lời

    a density-independent factor

  848. Thẻ 848

    Câu hỏi

    What is exponential population growth?

    Câu trả lời

    Growth at a constant per-capita rate, producing a J-shaped curve under ideal conditions.

  849. Thẻ 849

    Câu hỏi

    What is logistic population growth?

    Câu trả lời

    Growth that slows as population size approaches carrying capacity, producing an S-shaped model.

  850. Thẻ 850

    Câu hỏi

    What four processes directly change population size?

    Câu trả lời

    Births and immigration increase it; deaths and emigration decrease it.

  851. Thẻ 851

    Câu hỏi

    Under what conditions can exponential growth occur temporarily?

    Câu trả lời

    Resources are abundant and limiting effects such as competition, disease, and predation are weak.

  852. Thẻ 852

    Câu hỏi

    Which term describes J-shaped growth at constant per-capita rate?

    Câu trả lời

    exponential population growth

  853. Thẻ 853

    Câu hỏi

    Which term describes S-shaped growth that slows near carrying capacity?

    Câu trả lời

    logistic population growth

  854. Thẻ 854

    Câu hỏi

    Why is infectious disease often density dependent?

    Câu trả lời

    Close or frequent contact at high density increases transmission opportunities.

  855. Thẻ 855

    Câu hỏi

    Give an example of a density-independent population factor.

    Câu trả lời

    A severe storm, wildfire, drought, or freeze can affect populations regardless of their initial density.

  856. Thẻ 856

    Câu hỏi

    When is quadrat sampling useful?

    Câu trả lời

    For estimating abundance or frequency of sessile or slow-moving organisms in defined areas.

  857. Thẻ 857

    Câu hỏi

    What can a transect reveal?

    Câu trả lời

    How species occurrence or abundance changes along an environmental gradient.

  858. Thẻ 858

    Câu hỏi

    What can happen when a population overshoots carrying capacity?

    Câu trả lời

    Resource depletion may raise mortality or lower reproduction, causing decline or oscillation.

  859. Thẻ 859

    Câu hỏi

    What is the basic mark–recapture estimate of population size?

    Câu trả lời

    First sample marked × second sample total ÷ marked individuals recaptured.

  860. Thẻ 860

    Câu hỏi

    What assumptions improve a mark–recapture estimate?

    Câu trả lời

    Marks persist and do not affect survival, marked individuals mix, capture probability is similar, and the population is effectively closed.

  861. Thẻ 861

    Câu hỏi

    Why does a correlation between two population variables not prove causation?

    Câu trả lời

    A third factor, reverse influence, chance, or biased sampling could produce the association.

  862. Thẻ 862

    Câu hỏi

    What is a trophic level?

    Câu trả lời

    A feeding position in a food chain or web.

  863. Thẻ 863

    Câu hỏi

    What is a producer?

    Câu trả lời

    An autotroph that converts inorganic carbon into organic matter.

  864. Thẻ 864

    Câu hỏi

    What is a consumer?

    Câu trả lời

    An organism obtaining energy and matter by eating other organisms or organic material.

  865. Thẻ 865

    Câu hỏi

    What is a decomposer?

    Câu trả lời

    An organism that externally digests dead material and wastes and absorbs the products.

  866. Thẻ 866

    Câu hỏi

    Which term describes a feeding position in an ecosystem?

    Câu trả lời

    a trophic level

  867. Thẻ 867

    Câu hỏi

    Which term describes an autotroph forming organic matter?

    Câu trả lời

    a producer

  868. Thẻ 868

    Câu hỏi

    Which term describes an organism feeding on other organic matter?

    Câu trả lời

    a consumer

  869. Thẻ 869

    Câu hỏi

    Which term describes an organism digesting dead organic matter externally?

    Câu trả lời

    a decomposer

  870. Thẻ 870

    Câu hỏi

    What is a food chain?

    Câu trả lời

    A linear representation of feeding and energy-transfer relationships.

  871. Thẻ 871

    Câu hỏi

    What is a food web?

    Câu trả lời

    A network of interconnected feeding relationships in a community.

  872. Thẻ 872

    Câu hỏi

    What is gross primary productivity?

    Câu trả lời

    The total rate at which producers capture energy into organic matter.

  873. Thẻ 873

    Câu hỏi

    What is net primary productivity?

    Câu trả lời

    Producer energy stored as new biomass after subtracting producer respiration from gross primary productivity.

  874. Thẻ 874

    Câu hỏi

    Which term describes a linear feeding sequence?

    Câu trả lời

    a food chain

  875. Thẻ 875

    Câu hỏi

    Which term describes a network of connected food chains?

    Câu trả lời

    a food web

  876. Thẻ 876

    Câu hỏi

    Which term describes the total producer energy-capture rate?

    Câu trả lời

    gross primary productivity

  877. Thẻ 877

    Câu hỏi

    Which term describes producer biomass gain after respiration?

    Câu trả lời

    net primary productivity

  878. Thẻ 878

    Câu hỏi

    What is ecological productivity?

    Câu trả lời

    The rate of biomass or energy production per unit area or volume.

  879. Thẻ 879

    Câu hỏi

    What is a biogeochemical cycle?

    Câu trả lời

    Movement of an element or compound through organisms and the physical environment.

  880. Thẻ 880

    Câu hỏi

    Why is less energy available at each higher trophic level?

    Câu trả lời

    Not all biomass is eaten or digested, and organisms use energy in respiration, movement, maintenance, and heat loss.

  881. Thẻ 881

    Câu hỏi

    Why does energy flow rather than cycle through an ecosystem?

    Câu trả lời

    Energy enters mainly as light and ultimately disperses as heat, which ecosystems cannot fully recycle.

  882. Thẻ 882

    Câu hỏi

    Which term describes the rate of biomass or energy production?

    Câu trả lời

    ecological productivity

  883. Thẻ 883

    Câu hỏi

    Which term describes cycling of matter through living and nonliving reservoirs?

    Câu trả lời

    a biogeochemical cycle

  884. Thẻ 884

    Câu hỏi

    Why can matter cycle through an ecosystem?

    Câu trả lời

    Atoms are conserved and repeatedly transferred among organisms, detritus, soil, water, and atmosphere.

  885. Thẻ 885

    Câu hỏi

    Why is a pyramid of energy always upright?

    Câu trả lời

    Usable energy decreases between trophic levels because every transfer includes losses.

  886. Thẻ 886

    Câu hỏi

    How are gross and net primary productivity related?

    Câu trả lời

    NPP = GPP − producer respiration.

  887. Thẻ 887

    Câu hỏi

    How do decomposers support nutrient cycling?

    Câu trả lời

    They break down dead material and wastes, releasing inorganic nutrients for reuse.

  888. Thẻ 888

    Câu hỏi

    What processes move carbon rapidly between organisms and the atmosphere?

    Câu trả lời

    Photosynthesis removes carbon dioxide; respiration, decomposition, and combustion release it.

  889. Thẻ 889

    Câu hỏi

    Why is nitrogen fixation important?

    Câu trả lời

    It converts atmospheric nitrogen gas into forms that can enter biological nitrogen metabolism.

  890. Thẻ 890

    Câu hỏi

    How can excess nitrogen or phosphorus cause eutrophication?

    Câu trả lời

    Nutrient enrichment drives algal growth; decomposition of the biomass consumes oxygen and can create hypoxic water.

  891. Thẻ 891

    Câu hỏi

    Why can a persistent pollutant reach higher concentrations at higher trophic levels?

    Câu trả lời

    Predators consume contaminant stored in many prey, and the substance is not readily broken down or excreted.

  892. Thẻ 892

    Câu hỏi

    How is trophic-transfer efficiency calculated?

    Câu trả lời

    Energy or biomass gained by the higher trophic level ÷ energy or biomass available at the lower level × 100%.

  893. Thẻ 893

    Câu hỏi

    What is phenotypic variation?

    Câu trả lời

    Differences in observable traits among individuals of a population.

  894. Thẻ 894

    Câu hỏi

    What is heritable variation?

    Câu trả lời

    Trait differences that can be transmitted genetically to offspring.

  895. Thẻ 895

    Câu hỏi

    What is a selection pressure?

    Câu trả lời

    An environmental factor causing differences in survival or reproduction among phenotypes.

  896. Thẻ 896

    Câu hỏi

    What is relative fitness?

    Câu trả lời

    An individual's reproductive success compared with others in the population.

  897. Thẻ 897

    Câu hỏi

    Which term describes observable differences among individuals?

    Câu trả lời

    phenotypic variation

  898. Thẻ 898

    Câu hỏi

    Which term describes genetically transmissible trait differences?

    Câu trả lời

    heritable variation

  899. Thẻ 899

    Câu hỏi

    Which term describes an environmental factor producing differential reproductive success?

    Câu trả lời

    a selection pressure

  900. Thẻ 900

    Câu hỏi

    Which term describes reproductive success relative to other individuals?

    Câu trả lời

    relative fitness

  901. Thẻ 901

    Câu hỏi

    What is directional selection?

    Câu trả lời

    Selection favoring one extreme phenotype and shifting a population's trait distribution.

  902. Thẻ 902

    Câu hỏi

    What is stabilizing selection?

    Câu trả lời

    Selection favoring intermediate phenotypes and acting against extremes.

  903. Thẻ 903

    Câu hỏi

    What is disruptive selection?

    Câu trả lời

    Selection favoring both extreme phenotypes over intermediates.

  904. Thẻ 904

    Câu hỏi

    What is sexual selection?

    Câu trả lời

    Selection arising from differences in mating success.

  905. Thẻ 905

    Câu hỏi

    Which term describes selection shifting a trait toward one extreme?

    Câu trả lời

    directional selection

  906. Thẻ 906

    Câu hỏi

    Which term describes selection favoring intermediate phenotypes?

    Câu trả lời

    stabilizing selection

  907. Thẻ 907

    Câu hỏi

    Which term describes selection favoring both trait extremes?

    Câu trả lời

    disruptive selection

  908. Thẻ 908

    Câu hỏi

    Which term describes selection caused by unequal mating success?

    Câu trả lời

    sexual selection

  909. Thẻ 909

    Câu hỏi

    What conditions are required for natural selection?

    Câu trả lời

    Individuals vary, some variation is heritable, more offspring are produced than can reproduce, and variants differ in reproductive success.

  910. Thẻ 910

    Câu hỏi

    How does natural selection produce antibiotic-resistant bacterial populations?

    Câu trả lời

    Existing resistant variants survive treatment and reproduce more than susceptible bacteria.

  911. Thẻ 911

    Câu hỏi

    Does an antibiotic cause bacteria to mutate specifically toward resistance?

    Câu trả lời

    No. Resistance variants arise without regard to need; treatment selects among them.

  912. Thẻ 912

    Câu hỏi

    Can an individual become genetically adapted through natural selection?

    Câu trả lời

    No. Selection acts on individuals, but adaptation is a population change across generations.

  913. Thẻ 913

    Câu hỏi

    How does artificial selection differ from natural selection?

    Câu trả lời

    Humans choose breeding traits in artificial selection; environmental conditions determine differential reproduction in natural selection.

  914. Thẻ 914

    Câu hỏi

    How does natural selection change a population?

    Câu trả lời

    Individuals with advantageous heritable variants leave more offspring, increasing those alleles over generations.

  915. Thẻ 915

    Câu hỏi

    Why is fitness environment-dependent?

    Câu trả lời

    A trait that improves reproduction in one environment may be neutral or costly in another.

  916. Thẻ 916

    Câu hỏi

    How does genetic drift differ from natural selection?

    Câu trả lời

    Drift changes allele frequencies by chance sampling; selection changes them through consistent fitness differences.

  917. Thẻ 917

    Câu hỏi

    What is ecosystem stability?

    Câu trả lời

    The capacity of an ecosystem to maintain or recover its structure and functions despite disturbance.

  918. Thẻ 918

    Câu hỏi

    What is an ecological tipping point?

    Câu trả lời

    A threshold beyond which feedbacks can drive a large and difficult-to-reverse ecosystem shift.

  919. Thẻ 919

    Câu hỏi

    What is a mesocosm?

    Câu trả lời

    A controlled, simplified ecosystem used to investigate ecological processes under more realistic conditions than a small laboratory vessel.

  920. Thẻ 920

    Câu hỏi

    What is a sustainable yield?

    Câu trả lời

    A harvest rate that can continue without causing long-term resource decline under prevailing conditions.

  921. Thẻ 921

    Câu hỏi

    Which term describes the capacity of an ecosystem to persist or recover after disturbance?

    Câu trả lời

    ecosystem stability

  922. Thẻ 922

    Câu hỏi

    Which term describes a threshold triggering a major hard-to-reverse ecosystem shift?

    Câu trả lời

    an ecological tipping point

  923. Thẻ 923

    Câu hỏi

    Which term describes a controlled model ecosystem used for experiments?

    Câu trả lời

    a mesocosm

  924. Thẻ 924

    Câu hỏi

    Which term describes a harvest rate that avoids long-term depletion?

    Câu trả lời

    a sustainable yield

  925. Thẻ 925

    Câu hỏi

    What is eutrophication?

    Câu trả lời

    Nutrient enrichment of water that stimulates excess primary production and can lead to oxygen depletion.

  926. Thẻ 926

    Câu hỏi

    What is biomagnification?

    Câu trả lời

    Increase in concentration of a persistent pollutant at successively higher trophic levels.

  927. Thẻ 927

    Câu hỏi

    What is rewilding?

    Câu trả lời

    Ecosystem restoration that rebuilds natural processes, species interactions, and self-sustaining ecological function.

  928. Thẻ 928

    Câu hỏi

    What features can make an ecosystem more stable?

    Câu trả lời

    Diverse functional roles, connected habitats, intact food webs, nutrient cycling, and balancing feedbacks can help the system resist or recover from disturbance.

  929. Thẻ 929

    Câu hỏi

    Which term describes nutrient enrichment that can deplete oxygen in water?

    Câu trả lời

    eutrophication

  930. Thẻ 930

    Câu hỏi

    Which term describes increasing pollutant concentration up a food chain?

    Câu trả lời

    biomagnification

  931. Thẻ 931

    Câu hỏi

    Which term describes restoration focused on natural processes and self-sustaining ecosystems?

    Câu trả lời

    rewilding

  932. Thẻ 932

    Câu hỏi

    How could extensive Amazon deforestation push the ecosystem toward a tipping point?

    Câu trả lời

    Loss of trees can reduce rainfall recycling and increase heat and fire, which cause further forest loss and may shift large areas toward a drier state.

  933. Thẻ 933

    Câu hỏi

    What are a benefit and a limitation of using a mesocosm?

    Câu trả lời

    It allows controlled experiments with interacting organisms, but its simplified scale cannot reproduce every process or long-term influence in a natural ecosystem.

  934. Thẻ 934

    Câu hỏi

    Why should a fishery harvest below an uncertain maximum sustainable yield?

    Câu trả lời

    Population estimates and recruitment vary, so a safety margin reduces the chance that error or a poor breeding year drives long-term decline.

  935. Thẻ 935

    Câu hỏi

    How can intensive agriculture reduce ecosystem stability?

    Câu trả lời

    Habitat loss, low crop diversity, soil degradation, heavy water use, pesticides, and nutrient runoff can weaken food webs and ecosystem processes.

  936. Thẻ 936

    Câu hỏi

    Why can microplastic pollution harm aquatic ecosystems?

    Câu trả lời

    Small persistent particles can be ingested, carry additives or other pollutants, damage feeding and tissues, and move through food webs.

  937. Thẻ 937

    Câu hỏi

    How can rewilding improve ecosystem stability?

    Câu trả lời

    Restoring native species, habitat connections, and natural disturbance or grazing processes can rebuild feedbacks and allow the ecosystem to maintain itself with less intervention.

  938. Thẻ 938

    Câu hỏi

    What is the greenhouse effect?

    Câu trả lời

    Warming caused when atmospheric gases absorb and re-emit outgoing infrared radiation.

  939. Thẻ 939

    Câu hỏi

    What is a greenhouse gas?

    Câu trả lời

    An atmospheric gas that absorbs infrared radiation at wavelengths emitted by Earth.

  940. Thẻ 940

    Câu hỏi

    What is carbon dioxide (CO₂)?

    Câu trả lời

    A long-lived greenhouse gas increased mainly by fossil-fuel combustion, cement production, and land-use change.

  941. Thẻ 941

    Câu hỏi

    What is methane (CH₄)?

    Câu trả lời

    A potent greenhouse gas emitted by sources including fossil-fuel systems, livestock, rice cultivation, wetlands, and waste.

  942. Thẻ 942

    Câu hỏi

    Which term describes warming from absorption and re-emission of infrared radiation?

    Câu trả lời

    the greenhouse effect

  943. Thẻ 943

    Câu hỏi

    Which term describes an atmospheric infrared-absorbing gas?

    Câu trả lời

    a greenhouse gas

  944. Thẻ 944

    Câu hỏi

    Which term describes the long-lived greenhouse gas strongly increased by fossil fuels?

    Câu trả lời

    carbon dioxide (CO₂)

  945. Thẻ 945

    Câu hỏi

    Which term describes the potent short-lived greenhouse gas from biological and fossil sources?

    Câu trả lời

    methane (CH₄)

  946. Thẻ 946

    Câu hỏi

    What is albedo?

    Câu trả lời

    The fraction of incoming radiation reflected by a surface.

  947. Thẻ 947

    Câu hỏi

    What is a carbon sink?

    Câu trả lời

    A reservoir that absorbs more carbon than it releases over a specified period.

  948. Thẻ 948

    Câu hỏi

    What is ocean acidification?

    Câu trả lời

    Decline in seawater pH caused mainly by absorption of human-emitted carbon dioxide.

  949. Thẻ 949

    Câu hỏi

    What is climate change?

    Câu trả lời

    A persistent change in the statistical patterns of climate over decades or longer.

  950. Thẻ 950

    Câu hỏi

    Which term describes surface reflectivity?

    Câu trả lời

    albedo

  951. Thẻ 951

    Câu hỏi

    Which term describes a reservoir with net carbon uptake?

    Câu trả lời

    a carbon sink

  952. Thẻ 952

    Câu hỏi

    Which term describes seawater pH decline from absorbed carbon dioxide?

    Câu trả lời

    ocean acidification

  953. Thẻ 953

    Câu hỏi

    Which term describes long-term change in climate patterns?

    Câu trả lời

    climate change

  954. Thẻ 954

    Câu hỏi

    What is the enhanced greenhouse effect?

    Câu trả lời

    Additional warming caused by human-driven increases in greenhouse-gas concentrations.

  955. Thẻ 955

    Câu hỏi

    How do climate mitigation and climate adaptation differ?

    Câu trả lời

    Mitigation limits the magnitude of climate change; adaptation reduces harm from changes that occur.

  956. Thẻ 956

    Câu hỏi

    How does increasing greenhouse-gas concentration alter Earth's energy balance?

    Câu trả lời

    Less outgoing infrared energy initially escapes to space, so the climate warms until energy balance is restored at a higher temperature.

  957. Thẻ 957

    Câu hỏi

    How can melting ice amplify warming?

    Câu trả lời

    Less bright ice lowers albedo, so darker land or water absorbs more solar energy and causes further warming.

  958. Thẻ 958

    Câu hỏi

    How can climate change alter species distributions?

    Câu trả lời

    Temperature, rainfall, seasons, sea level, and interactions shift, moving or shrinking areas with suitable conditions.

  959. Thẻ 959

    Câu hỏi

    Why can ocean acidification harm calcifying organisms?

    Câu trả lời

    Carbonate chemistry changes, reducing availability of carbonate ions used to build calcium-carbonate structures.

  960. Thẻ 960

    Câu hỏi

    How can ecosystem protection contribute to climate mitigation?

    Câu trả lời

    Protecting forests, wetlands, soils, and coastal habitats can avoid emissions and maintain or increase carbon storage.

Luminous sequence of molecular forms, a cell, a leaf and animal silhouette, and a water ecosystem on a dark blue background.

960 thẻ

IB Biology SL Flashcards: Complete Course Review

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