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.
A pakliról
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.
Kártyák ebben a pakliban
1. kártya
Kérdés
What is water polarity?
Válasz
The unequal sharing of electrons in a water molecule, giving oxygen a partial negative charge and the hydrogens partial positive charges.
2. kártya
Kérdés
What is a hydrogen bond?
Válasz
A weak attraction between a partially positive hydrogen atom and a partially negative atom in another molecule.
3. kártya
Kérdés
What is cohesion?
Válasz
Attraction between molecules of the same substance.
4. kártya
Kérdés
What is adhesion?
Válasz
Attraction between molecules of different substances.
5. kártya
Kérdés
Which term describes unequal charge distribution within a water molecule?
Válasz
water polarity
6. kártya
Kérdés
Which term describes the intermolecular attraction that links neighboring water molecules?
Válasz
a hydrogen bond
7. kártya
Kérdés
Which term describes attraction between molecules of the same substance?
Válasz
cohesion
8. kártya
Kérdés
Which term describes attraction between water and a different material?
Válasz
adhesion
9. kártya
Kérdés
What is a solvent?
Válasz
A liquid that dissolves solutes to form a solution.
10. kártya
Kérdés
What is specific heat capacity?
Válasz
The energy required to raise the temperature of a unit mass of a substance by one degree.
11. kártya
Kérdés
What is latent heat of vaporization?
Válasz
The energy required to vaporize a specified amount of liquid without changing its temperature.
12. kártya
Kérdés
Why does ice float on liquid water?
Válasz
Hydrogen bonds hold water molecules in an open lattice in ice, making ice less dense than liquid water.
13. kártya
Kérdés
Which term describes a liquid that dissolves solutes?
Válasz
a solvent
14. kártya
Kérdés
Which term describes the energy needed to raise a unit mass by one degree?
Válasz
specific heat capacity
15. kártya
Kérdés
Which term describes the energy needed to vaporize a liquid without a temperature change?
Válasz
latent heat of vaporization
16. kártya
Kérdés
Which property of water makes sweating an effective cooling mechanism?
Válasz
Water absorbs substantial energy as it evaporates; the highest-energy molecules leave, carrying heat away from the skin.
17. kártya
Kérdés
Why does water resist rapid temperature change?
Válasz
Many hydrogen bonds must absorb energy before molecular motion increases substantially, giving water a high specific heat capacity.
18. kártya
Kérdés
How do cohesion and adhesion support water transport in narrow tubes?
Válasz
Cohesion keeps water molecules connected, while adhesion helps the water column cling to the tube wall.
19. kártya
Kérdés
How does water participate differently in hydrolysis and condensation?
Válasz
Hydrolysis consumes water to split a bond; condensation forms a bond and releases water.
20. kártya
Kérdés
How does floating ice protect aquatic life in winter?
Válasz
Surface ice insulates the liquid water below, slowing further heat loss and preventing the whole body of water from freezing rapidly.
21. kártya
Kérdés
Why is water effective for transporting many biological solutes?
Válasz
Its polarity allows ions and other polar molecules to become surrounded and dispersed in solution.
22. kártya
Kérdés
Why do nonpolar substances tend to cluster in water?
Válasz
Clustering reduces the nonpolar surface exposed to water, allowing more water molecules to maintain hydrogen-bond interactions.
23. kártya
Kérdés
What is a nucleotide?
Válasz
A nucleic-acid monomer made of a pentose sugar, a phosphate group, and a nitrogenous base.
24. kártya
Kérdés
What is a nucleoside?
Válasz
A nitrogenous base joined to a pentose sugar, without a phosphate group.
25. kártya
Kérdés
What is a phosphodiester bond?
Válasz
A covalent bond linking the phosphate of one nucleotide to the sugar of the next nucleotide.
26. kártya
Kérdés
What is DNA?
Válasz
A usually double-stranded nucleic acid that stores hereditary information in its base sequence.
27. kártya
Kérdés
Which term describes a sugar-phosphate-base monomer?
Válasz
a nucleotide
28. kártya
Kérdés
Which term describes a base joined to a sugar but no phosphate?
Válasz
a nucleoside
29. kártya
Kérdés
Which term describes the covalent linkage in a nucleic-acid sugar-phosphate backbone?
Válasz
a phosphodiester bond
30. kártya
Kérdés
Which term describes the nucleic acid that usually stores hereditary information?
Válasz
DNA
31. kártya
Kérdés
What is RNA?
Válasz
A usually single-stranded nucleic acid involved in expressing and regulating genetic information.
32. kártya
Kérdés
What are antiparallel DNA strands?
Válasz
Two DNA strands that run in opposite 5′ to 3′ directions.
33. kártya
Kérdés
What is complementary base pairing?
Válasz
Specific pairing in which adenine pairs with thymine in DNA, or uracil in RNA, and cytosine pairs with guanine.
34. kártya
Kérdés
What is a purine?
Válasz
A nitrogenous base with two fused rings; adenine and guanine are purines.
35. kártya
Kérdés
Which term describes the usually single-stranded nucleic acid used in gene expression?
Válasz
RNA
36. kártya
Kérdés
Which term describes DNA strands running in opposite directions?
Válasz
antiparallel DNA strands
37. kártya
Kérdés
Which term describes specific A–T or A–U and C–G pairing?
Válasz
complementary base pairing
38. kártya
Kérdés
Which term describes a two-ring nitrogenous base?
Válasz
a purine
39. kártya
Kérdés
What is a pyrimidine?
Válasz
A nitrogenous base with one ring; cytosine, thymine, and uracil are pyrimidines.
40. kártya
Kérdés
What is a genome?
Válasz
The complete genetic material of an organism or cell.
41. kártya
Kérdés
What three structural features commonly distinguish RNA from DNA?
Válasz
RNA usually contains ribose, uses uracil instead of thymine, and is single-stranded rather than double-stranded.
42. kártya
Kérdés
What determines the base sequence of the second DNA strand?
Válasz
Complementary base-pairing rules determine it: A pairs with T, and C pairs with G.
43. kártya
Kérdés
Which term describes a one-ring nitrogenous base?
Válasz
a pyrimidine
44. kártya
Kérdés
Which term describes the complete genetic material of an organism?
Válasz
a genome
45. kártya
Kérdés
What do the 5′ and 3′ labels of a nucleic-acid strand refer to?
Válasz
They refer to numbered carbon atoms in the pentose sugar and define the strand's chemical direction.
46. kártya
Kérdés
Where is genetic information encoded in DNA?
Válasz
In the order of nitrogenous bases along the DNA strand.
47. kártya
Kérdés
Why is ATP classified as a nucleotide?
Válasz
It contains adenine, ribose, and phosphate groups, the three component types of a nucleotide.
48. kártya
Kérdés
How do mRNA, tRNA, and rRNA contribute to protein synthesis?
Válasz
mRNA carries the coding sequence, tRNA delivers amino acids, and rRNA forms the catalytic and structural core of ribosomes.
49. kártya
Kérdés
How are a gene and a chromosome related?
Válasz
A gene is a DNA sequence with a biological function; a chromosome is one long DNA molecule containing many genes and other sequences.
50. kártya
Kérdés
What happens to double-stranded DNA when it is denatured by heat?
Válasz
Hydrogen bonds between complementary bases break and the two strands separate; the covalent backbones usually remain intact.
51. kártya
Kérdés
Why can each DNA strand serve as a template during replication?
Válasz
Its base sequence determines a complementary sequence through specific base pairing.
52. kártya
Kérdés
In which direction are new nucleic-acid strands synthesized?
Válasz
Nucleotides are added to the 3′ end, so synthesis proceeds 5′ to 3′.
53. kártya
Kérdés
What is a monosaccharide?
Válasz
A single sugar unit that can serve as a carbohydrate monomer.
54. kártya
Kérdés
What is a disaccharide?
Válasz
A carbohydrate formed from two monosaccharides joined by a glycosidic bond.
55. kártya
Kérdés
What is a polysaccharide?
Válasz
A polymer made from many monosaccharide units.
56. kártya
Kérdés
What is a glycosidic bond?
Válasz
A covalent bond joining monosaccharides in a carbohydrate.
57. kártya
Kérdés
Which term describes a single sugar unit?
Válasz
a monosaccharide
58. kártya
Kérdés
Which term describes two monosaccharides joined together?
Válasz
a disaccharide
59. kártya
Kérdés
Which term describes a polymer of many sugar units?
Válasz
a polysaccharide
60. kártya
Kérdés
Which term describes the covalent linkage between monosaccharides?
Válasz
a glycosidic bond
61. kártya
Kérdés
What is a triglyceride?
Válasz
A lipid formed from glycerol joined to three fatty acids.
62. kártya
Kérdés
What is a fatty acid?
Válasz
A hydrocarbon chain with a carboxyl group that can form part of many lipids.
63. kártya
Kérdés
What is a saturated fatty acid?
Válasz
A fatty acid with no carbon-carbon double bonds in its hydrocarbon chain.
64. kártya
Kérdés
What is a phospholipid?
Válasz
An amphipathic lipid with a phosphate-containing hydrophilic head and hydrophobic fatty-acid tails.
65. kártya
Kérdés
Which term describes glycerol joined to three fatty acids?
Válasz
a triglyceride
66. kártya
Kérdés
Which term describes a hydrocarbon chain ending in a carboxyl group?
Válasz
a fatty acid
67. kártya
Kérdés
Which term describes a fatty acid without carbon-carbon double bonds?
Válasz
a saturated fatty acid
68. kártya
Kérdés
Which term describes a lipid with a polar head and nonpolar tails?
Válasz
a phospholipid
69. kártya
Kérdés
How is a glycosidic bond formed between two monosaccharides?
Válasz
A condensation reaction joins them and releases a molecule of water.
70. kártya
Kérdés
How is a polysaccharide broken into smaller sugars?
Válasz
Hydrolysis adds water across glycosidic bonds, splitting the polymer.
71. kártya
Kérdés
Which polysaccharides store glucose in plants and animals?
Válasz
Starch stores glucose in plants; glycogen stores glucose in animals and fungi.
72. kártya
Kérdés
Why is cellulose suitable for plant cell walls?
Válasz
Its straight β-glucose chains hydrogen-bond into strong microfibrils that resist stretching.
73. kártya
Kérdés
Why do lipids store more energy per gram than carbohydrates?
Válasz
Lipids contain more energy-rich carbon-hydrogen bonds and are more reduced.
74. kártya
Kérdés
Why do phospholipids form bilayers in water?
Válasz
Hydrophilic heads interact with water while hydrophobic tails cluster away from water.
75. kártya
Kérdés
Besides energy storage, what are three biological roles of lipids?
Válasz
They form membranes, provide thermal insulation and cushioning, and can act as signaling molecules.
76. kártya
Kérdés
How do cis double bonds affect fatty-acid packing and melting point?
Válasz
They introduce bends that reduce close packing, usually lowering the melting point.
77. kártya
Kérdés
What is an amino acid?
Válasz
A protein monomer with an amino group, a carboxyl group, a hydrogen, and a variable R group attached to a central carbon.
78. kártya
Kérdés
What is a peptide bond?
Válasz
The covalent bond formed between the amino group of one amino acid and the carboxyl group of another.
79. kártya
Kérdés
What is a polypeptide?
Válasz
A chain of amino acids joined by peptide bonds.
80. kártya
Kérdés
What is protein primary structure?
Válasz
The amino-acid sequence of a polypeptide.
81. kártya
Kérdés
Which term describes a protein monomer with amino, carboxyl, and variable R groups?
Válasz
an amino acid
82. kártya
Kérdés
Which term describes the covalent linkage between amino acids?
Válasz
a peptide bond
83. kártya
Kérdés
Which term describes a chain of peptide-linked amino acids?
Válasz
a polypeptide
84. kártya
Kérdés
Which term describes a protein's amino-acid sequence?
Válasz
protein primary structure
85. kártya
Kérdés
What is protein secondary structure?
Válasz
Local folding such as α-helices and β-sheets stabilized mainly by backbone hydrogen bonds.
86. kártya
Kérdés
What is protein tertiary structure?
Válasz
The overall three-dimensional shape of one polypeptide produced by interactions among R groups and the backbone.
87. kártya
Kérdés
What is protein quaternary structure?
Válasz
The arrangement of multiple polypeptide subunits in one functional protein.
88. kártya
Kérdés
What is protein denaturation?
Válasz
Loss of a protein's normal three-dimensional shape and therefore usually its function.
89. kártya
Kérdés
Which term describes local α-helix and β-sheet folding?
Válasz
protein secondary structure
90. kártya
Kérdés
Which term describes the overall three-dimensional shape of one polypeptide?
Válasz
protein tertiary structure
91. kártya
Kérdés
Which term describes the association of multiple polypeptide subunits?
Válasz
protein quaternary structure
92. kártya
Kérdés
Which term describes loss of a protein's native shape?
Válasz
protein denaturation
93. kártya
Kérdés
What mainly gives different amino acids their different chemical properties?
Válasz
Their variable R groups.
94. kártya
Kérdés
What reaction forms a peptide bond?
Válasz
A condensation reaction releases water as the amino and carboxyl groups join.
95. kártya
Kérdés
Why can high temperature denature a protein?
Válasz
Increased molecular motion disrupts weak interactions that maintain the protein's shape.
96. kártya
Kérdés
Why can extreme pH denature a protein?
Válasz
It changes the charges of R groups and disrupts ionic and hydrogen-bond interactions.
97. kártya
Kérdés
How do fibrous and globular proteins generally differ?
Válasz
Fibrous proteins are elongated and mainly structural; globular proteins are compact and often perform dynamic functions.
98. kártya
Kérdés
Why is three-dimensional shape crucial to protein function?
Válasz
It creates specific binding, catalytic, structural, or interaction surfaces.
99. kártya
Kérdés
Name four broad biological roles of proteins.
Válasz
Catalysis, transport, signaling, defense, movement, and structural support are major roles; any four are sufficient.
100. kártya
Kérdés
How can changing one amino acid alter protein function?
Válasz
The substitution can change R-group interactions, folding, stability, or an active or binding site.
101. kártya
Kérdés
What is cell theory?
Válasz
The principles that living organisms are made of cells, cells are the basic units of life, and cells arise from pre-existing cells.
102. kártya
Kérdés
What is a prokaryotic cell?
Válasz
A cell without a nucleus or other membrane-bound organelles.
103. kártya
Kérdés
What is a eukaryotic cell?
Válasz
A cell with DNA enclosed in a nucleus and with membrane-bound organelles.
104. kártya
Kérdés
What is the nucleus?
Válasz
The double-membrane organelle that contains most of a eukaryotic cell's DNA.
105. kártya
Kérdés
Which term describes the principles describing cells as life's basic units?
Válasz
cell theory
106. kártya
Kérdés
Which term describes a cell lacking a nucleus and membrane-bound organelles?
Válasz
a prokaryotic cell
107. kártya
Kérdés
Which term describes a cell with a nucleus and membrane-bound organelles?
Válasz
a eukaryotic cell
108. kártya
Kérdés
Which term describes the organelle containing most eukaryotic DNA?
Válasz
the nucleus
109. kártya
Kérdés
What is a ribosome?
Válasz
A molecular complex of rRNA and proteins that synthesizes polypeptides.
110. kártya
Kérdés
What is the cytoplasm?
Válasz
The material inside the plasma membrane but outside the nucleus, including cytosol and organelles.
111. kártya
Kérdés
What is the plasma membrane?
Válasz
The selectively permeable boundary separating a cell from its environment.
112. kártya
Kérdés
What is a cell wall?
Válasz
A rigid extracellular layer that supports and protects cells in plants, fungi, and most prokaryotes.
113. kártya
Kérdés
Which term describes the complex that synthesizes polypeptides?
Válasz
a ribosome
114. kártya
Kérdés
Which term describes cell contents inside the plasma membrane but outside the nucleus?
Válasz
the cytoplasm
115. kártya
Kérdés
Which term describes the selectively permeable cell boundary?
Válasz
the plasma membrane
116. kártya
Kérdés
Which term describes a rigid extracellular support layer?
Válasz
a cell wall
117. kártya
Kérdés
What is the nucleoid?
Válasz
The non-membrane-bound region containing the main chromosome of a prokaryotic cell.
118. kártya
Kérdés
What is the cytoskeleton?
Válasz
A dynamic network of protein filaments involved in cell shape, transport, division, and movement.
119. kártya
Kérdés
What structures are shared by all cells?
Válasz
A plasma membrane, cytoplasm, genetic material, and ribosomes.
120. kártya
Kérdés
Which structures distinguish a typical plant cell from a typical animal cell?
Válasz
A plant cell has a cellulose wall, chloroplasts in photosynthetic tissues, and a large central vacuole; an animal cell lacks these.
121. kártya
Kérdés
Which term describes the prokaryotic chromosome-containing region?
Válasz
the nucleoid
122. kártya
Kérdés
Which term describes the internal network of protein filaments?
Válasz
the cytoskeleton
123. kártya
Kérdés
How is genetic material commonly organized in a prokaryotic cell?
Válasz
The main DNA is usually one circular chromosome in the nucleoid, often accompanied by smaller plasmids.
124. kártya
Kérdés
How is microscope magnification calculated?
Válasz
Magnification = image size ÷ actual size, using the same units.
125. kártya
Kérdés
What does microscope resolution describe?
Válasz
The ability to distinguish two close points as separate.
126. kártya
Kérdés
Arrange these from smallest to largest: ribosome, bacterium, animal cell.
Válasz
Ribosome, bacterium, animal cell.
127. kártya
Kérdés
How does the cytoskeleton support intracellular transport?
Válasz
Motor proteins move vesicles and other cargo along cytoskeletal filaments.
128. kártya
Kérdés
Why does a small cell usually exchange materials more efficiently than a geometrically similar large cell?
Válasz
It has a larger surface-area-to-volume ratio, providing more exchange surface per unit of cell contents.
129. kártya
Kérdés
Why is a cell more than a collection of isolated molecules?
Válasz
Organized interactions among components produce emergent functions such as metabolism, regulation, and reproduction.
130. kártya
Kérdés
What major advantage do membrane-bound organelles give eukaryotic cells?
Válasz
They separate incompatible reactions and create specialized local conditions.
131. kártya
Kérdés
What is a phospholipid bilayer?
Válasz
A double layer of phospholipids with hydrophilic heads facing water and hydrophobic tails facing inward.
132. kártya
Kérdés
What is the fluid mosaic model?
Válasz
A model describing membranes as mobile phospholipids containing a changing mosaic of proteins and other components.
133. kártya
Kérdés
What is an integral membrane protein?
Válasz
A protein embedded in the bilayer, often spanning it.
134. kártya
Kérdés
What is a peripheral membrane protein?
Válasz
A protein attached to a membrane surface rather than embedded in the bilayer.
135. kártya
Kérdés
Which term describes a double phospholipid layer with inward-facing tails?
Válasz
a phospholipid bilayer
136. kártya
Kérdés
Which term describes the model of a mobile lipid layer containing varied proteins?
Válasz
the fluid mosaic model
137. kártya
Kérdés
Which term describes a protein embedded within the lipid bilayer?
Válasz
an integral membrane protein
138. kártya
Kérdés
Which term describes a protein attached to a membrane surface?
Válasz
a peripheral membrane protein
139. kártya
Kérdés
What is membrane cholesterol?
Válasz
An amphipathic lipid that buffers membrane fluidity and reduces permeability in animal cells.
140. kártya
Kérdés
What is a glycoprotein?
Válasz
A protein with an attached carbohydrate chain, often used in recognition, adhesion, or signaling.
141. kártya
Kérdés
What is diffusion?
Válasz
Net movement of particles from a region of higher concentration to lower concentration due to random motion.
142. kártya
Kérdés
What is osmosis?
Válasz
Net movement of water across a selectively permeable membrane from higher water potential to lower water potential.
143. kártya
Kérdés
Which term describes the animal-membrane lipid that buffers fluidity?
Válasz
membrane cholesterol
144. kártya
Kérdés
Which term describes a carbohydrate-bearing protein?
Válasz
a glycoprotein
145. kártya
Kérdés
Which term describes net movement down a concentration gradient?
Válasz
diffusion
146. kártya
Kérdés
Which term describes net water movement across a selectively permeable membrane?
Válasz
osmosis
147. kártya
Kérdés
What is facilitated diffusion?
Válasz
Passive movement down a gradient through a membrane channel or carrier protein.
148. kártya
Kérdés
What is active transport?
Válasz
Energy-requiring movement of a substance against its concentration or electrochemical gradient.
149. kártya
Kérdés
Why is the phospholipid bilayer selectively permeable?
Válasz
Its hydrophobic interior allows small nonpolar molecules through more readily than ions and most large or polar molecules.
150. kártya
Kérdés
How do simple diffusion and facilitated diffusion differ?
Válasz
Both are passive, but facilitated diffusion uses specific membrane proteins while simple diffusion passes through the bilayer.
151. kártya
Kérdés
Which term describes passive transport through a channel or carrier?
Válasz
facilitated diffusion
152. kártya
Kérdés
Which term describes energy-dependent transport against a gradient?
Válasz
active transport
153. kártya
Kérdés
How do channel and carrier proteins differ?
Válasz
Channels provide hydrophilic pores; carriers bind solutes and change shape to move them.
154. kártya
Kérdés
How can an ATP-driven pump maintain an ion gradient?
Válasz
It couples ATP hydrolysis to a conformational change that moves ions against their electrochemical gradient.
155. kártya
Kérdés
How does endocytosis move material into a cell?
Válasz
The plasma membrane folds inward and pinches off a vesicle containing the material.
156. kártya
Kérdés
How does exocytosis move material out of a cell?
Válasz
An intracellular vesicle fuses with the plasma membrane and releases its contents outside.
157. kártya
Kérdés
What happens to an animal cell in a strongly hypotonic solution?
Válasz
Water enters by osmosis; without a cell wall, the cell may swell and lyse.
158. kártya
Kérdés
Does molecular movement stop when diffusion reaches equilibrium?
Válasz
No. Molecules continue moving randomly, but there is no net movement between regions.
159. kártya
Kérdés
How does decreasing temperature generally affect membrane fluidity?
Válasz
It reduces phospholipid movement and makes the membrane less fluid.
160. kártya
Kérdés
Why do unsaturated fatty-acid tails increase membrane fluidity?
Válasz
Their cis double-bond bends prevent phospholipids from packing tightly.
161. kártya
Kérdés
What changes increase the rate of simple diffusion across a membrane?
Válasz
A steeper gradient, larger surface area, higher temperature, shorter distance, and greater membrane permeability increase the rate.
162. kártya
Kérdés
What is a mitochondrion?
Válasz
A double-membrane organelle where most aerobic ATP production occurs.
163. kártya
Kérdés
What is a chloroplast?
Válasz
A double-membrane organelle where photosynthesis occurs in plants and algae.
164. kártya
Kérdés
What is rough endoplasmic reticulum?
Válasz
A membrane network bearing ribosomes that synthesizes and begins processing many secreted and membrane proteins.
165. kártya
Kérdés
What is smooth endoplasmic reticulum?
Válasz
A membrane network involved in lipid synthesis, detoxification, and calcium storage.
166. kártya
Kérdés
Which term describes the main organelle of aerobic ATP production?
Válasz
a mitochondrion
167. kártya
Kérdés
Which term describes the photosynthetic organelle of plants and algae?
Válasz
a chloroplast
168. kártya
Kérdés
Which term describes the ribosome-studded membrane network?
Válasz
rough endoplasmic reticulum
169. kártya
Kérdés
Which term describes the membrane network that lacks ribosomes and synthesizes lipids?
Válasz
smooth endoplasmic reticulum
170. kártya
Kérdés
What is the Golgi apparatus?
Válasz
Stacked membranes that modify, sort, and package proteins and lipids into vesicles.
171. kártya
Kérdés
What is a lysosome?
Válasz
An acidic enzyme-containing organelle that digests macromolecules and worn cellular components.
172. kártya
Kérdés
What is a vesicle?
Válasz
A small membrane-bound compartment used for transport, storage, or chemical reactions.
173. kártya
Kérdés
What is the central vacuole?
Válasz
A large plant-cell compartment that stores solutes and helps maintain turgor pressure.
174. kártya
Kérdés
Which term describes the organelle that modifies and sorts cellular cargo?
Válasz
the Golgi apparatus
175. kártya
Kérdés
Which term describes the acidic digestive organelle?
Válasz
a lysosome
176. kártya
Kérdés
Which term describes a small membrane-bound transport compartment?
Válasz
a vesicle
177. kártya
Kérdés
Which term describes the large plant compartment that supports turgor?
Válasz
the central vacuole
178. kártya
Kérdés
Why can compartmentalization increase metabolic efficiency?
Válasz
It concentrates enzymes and substrates, maintains suitable local conditions, and separates incompatible reactions.
179. kártya
Kérdés
How do mitochondrial cristae support ATP production?
Válasz
They increase inner-membrane area for electron transport chains and ATP synthase.
180. kártya
Kérdés
Why are chloroplast thylakoids arranged as extensive membranes?
Válasz
They provide a large surface for light-absorbing complexes, electron transport chains, and ATP synthase.
181. kártya
Kérdés
What is the main function of the nucleolus?
Válasz
It produces rRNA and assembles ribosomal subunits.
182. kártya
Kérdés
Trace a secreted protein from synthesis to release.
Válasz
Ribosome on rough ER → ER lumen → transport vesicle → Golgi apparatus → secretory vesicle → plasma membrane → exocytosis.
183. kártya
Kérdés
Why does a lysosome maintain an acidic interior?
Válasz
Its hydrolytic enzymes work best at low pH, and acidity helps confine their activity from the cytosol.
184. kártya
Kérdés
How do the nucleus, ribosomes, ER, and Golgi cooperate in protein production?
Válasz
DNA instructions are transcribed in the nucleus; ribosomes translate them; ER folds or modifies many products; Golgi further modifies and sorts them.
185. kártya
Kérdés
How are transport vesicles directed to the correct target membrane?
Válasz
Specific recognition proteins on vesicles and target membranes interact, allowing selective docking and fusion.
186. kártya
Kérdés
What is cell differentiation?
Válasz
The process by which a cell develops specialized structure and function.
187. kártya
Kérdés
What is a stem cell?
Válasz
An unspecialized cell able to self-renew and produce differentiated cells.
188. kártya
Kérdés
What is gene expression?
Válasz
Use of genetic information to produce a functional RNA or protein product.
189. kártya
Kérdés
What is a tissue?
Válasz
A coordinated group of similar or related cells performing a shared function.
190. kártya
Kérdés
Which term describes development of specialized cell structure and function?
Válasz
cell differentiation
191. kártya
Kérdés
Which term describes an unspecialized self-renewing cell?
Válasz
a stem cell
192. kártya
Kérdés
Which term describes production of a functional product from genetic information?
Válasz
gene expression
193. kártya
Kérdés
Which term describes a group of coordinated cells with a shared function?
Válasz
a tissue
194. kártya
Kérdés
What is an organ?
Válasz
A structure made of multiple tissues working together for particular functions.
195. kártya
Kérdés
What is the organ-system level of biological organization?
Válasz
A group of organs that coordinate to perform major functions for an organism.
196. kártya
Kérdés
What is surface-area-to-volume ratio?
Válasz
The amount of surface area available relative to the volume it must serve.
197. kártya
Kérdés
How can two specialized cells have the same genome but different structures?
Válasz
They express different sets and amounts of genes, producing different proteins and cellular features.
198. kártya
Kérdés
Which term describes a structure composed of multiple tissue types?
Válasz
an organ
199. kártya
Kérdés
Which term describes the level of biological organization formed by coordinated organs?
Válasz
an organ system
200. kártya
Kérdés
Which term describes surface area available per unit volume?
Válasz
surface-area-to-volume ratio
201. kártya
Kérdés
How is a mammalian red blood cell specialized for oxygen transport?
Válasz
Its biconcave shape increases exchange area, it is flexible, and loss of its nucleus leaves more space for hemoglobin.
202. kártya
Kérdés
How is a sperm cell specialized for fertilization?
Válasz
It has a flagellum for movement, many mitochondria for ATP, a haploid nucleus, and an acrosome containing enzymes.
203. kártya
Kérdés
How is a neuron specialized for rapid communication?
Válasz
Long processes carry signals over distance, branching dendrites receive inputs, and synaptic terminals transmit signals to other cells.
204. kártya
Kérdés
How is a root hair cell specialized for mineral and water uptake?
Válasz
Its long projection increases surface area, its thin wall shortens the pathway, and membrane transport proteins take up ions.
205. kártya
Kérdés
How is a palisade mesophyll cell specialized for photosynthesis?
Válasz
It contains many chloroplasts and is positioned near the upper leaf surface where light is strongest.
206. kártya
Kérdés
How do ciliated epithelial cells help protect airways?
Válasz
Their cilia move mucus containing trapped particles and microbes toward the throat.
207. kártya
Kérdés
Why can extreme specialization reduce a cell's independence?
Válasz
Resources and structures are committed to a narrow role, so the cell depends on other cells for functions it no longer performs well.
208. kártya
Kérdés
What is water potential?
Válasz
The potential energy of water per unit volume relative to pure water, used to predict the direction of water movement.
209. kártya
Kérdés
What is solute potential?
Válasz
The negative contribution of dissolved solutes to water potential.
210. kártya
Kérdés
What is pressure potential?
Válasz
The contribution of physical pressure to water potential.
211. kártya
Kérdés
What is turgor pressure?
Válasz
Outward pressure of a plant-cell interior against its cell wall after water uptake.
212. kártya
Kérdés
Which term describes the tendency of water to move relative to pure water?
Válasz
water potential
213. kártya
Kérdés
Which term describes the water-potential component lowered by dissolved solutes?
Válasz
solute potential
214. kártya
Kérdés
Which term describes the water-potential component caused by physical pressure?
Válasz
pressure potential
215. kártya
Kérdés
Which term describes pressure of plant-cell contents against the wall?
Válasz
turgor pressure
216. kártya
Kérdés
What is plasmolysis?
Válasz
Separation of the plasma membrane from the cell wall after a plant cell loses water.
217. kártya
Kérdés
What is a flaccid plant cell?
Válasz
A plant cell with insufficient turgor pressure to be firm.
218. kártya
Kérdés
What is an isotonic condition?
Válasz
A condition in which two solutions have equal effective water potential and no net water movement occurs.
219. kártya
Kérdés
In which direction does water move across a permeable membrane?
Válasz
From higher water potential to lower water potential.
220. kártya
Kérdés
Which term describes membrane separation from the plant cell wall after water loss?
Válasz
plasmolysis
221. kártya
Kérdés
Which term describes a plant cell lacking firm turgor?
Válasz
a flaccid plant cell
222. kártya
Kérdés
Which term describes equal effective water potential across a membrane?
Válasz
an isotonic condition
223. kártya
Kérdés
What is the water potential of pure water at standard pressure?
Válasz
Zero; adding solute makes water potential more negative.
224. kártya
Kérdés
How are water potential, solute potential, and pressure potential related?
Válasz
Water potential equals solute potential plus pressure potential: Ψ = Ψs + Ψp.
225. kártya
Kérdés
Why does a plant cell usually become turgid rather than burst in a hypotonic solution?
Válasz
Water entry raises pressure potential, while the rigid cell wall resists further expansion.
226. kártya
Kérdés
What happens to a plant cell placed in a solution with much lower water potential?
Válasz
Water leaves the cell, turgor falls, and severe loss can cause plasmolysis.
227. kártya
Kérdés
Can two solutions have different solute concentrations but equal water potential?
Válasz
Yes. A difference in pressure potential can offset a difference in solute potential.
228. kártya
Kérdés
What is an enzyme?
Válasz
A biological catalyst that increases reaction rate without being consumed.
229. kártya
Kérdés
What is an active site?
Válasz
The region of an enzyme where substrate binds and catalysis occurs.
230. kártya
Kérdés
What is a substrate?
Válasz
A reactant molecule on which an enzyme acts.
231. kártya
Kérdés
What is activation energy?
Válasz
The minimum energy input needed for a reaction to begin.
232. kártya
Kérdés
Which term describes a biological catalyst?
Válasz
an enzyme
233. kártya
Kérdés
Which term describes the substrate-binding catalytic region of an enzyme?
Válasz
an active site
234. kártya
Kérdés
Which term describes a reactant bound and changed by an enzyme?
Válasz
a substrate
235. kártya
Kérdés
Which term describes the energy barrier that must be overcome for a reaction?
Válasz
activation energy
236. kártya
Kérdés
What is the induced-fit model?
Válasz
The model in which substrate binding changes active-site shape to improve catalytic interactions.
237. kártya
Kérdés
What is enzyme denaturation?
Válasz
Loss of the active three-dimensional shape of an enzyme, usually causing loss of activity.
238. kártya
Kérdés
What is competitive inhibition?
Válasz
Inhibition caused by a molecule competing with substrate for the active site.
239. kártya
Kérdés
What is noncompetitive inhibition?
Válasz
Inhibition caused by binding away from the active site and reducing catalytic function.
240. kártya
Kérdés
Which term describes the model where substrate binding reshapes the active site?
Válasz
the induced-fit model
241. kártya
Kérdés
Which term describes loss of an enzyme's functional shape?
Válasz
enzyme denaturation
242. kártya
Kérdés
Which term describes inhibition by active-site competition?
Válasz
competitive inhibition
243. kártya
Kérdés
Which term describes inhibition by binding outside the active site?
Válasz
noncompetitive inhibition
244. kártya
Kérdés
What is an enzyme optimum?
Válasz
The condition, such as temperature or pH, at which an enzyme's activity is highest.
245. kártya
Kérdés
What is feedback inhibition?
Válasz
Control in which a pathway product inhibits an enzyme acting earlier in the pathway.
246. kártya
Kérdés
How does an enzyme increase reaction rate?
Válasz
It stabilizes the transition state and provides a pathway with lower activation energy.
247. kártya
Kérdés
Why does enzyme activity often rise and then fall as temperature increases?
Válasz
Molecular collisions initially increase, but excessive heat disrupts enzyme shape and denatures the active site.
248. kártya
Kérdés
Which term describes the condition producing maximum enzyme activity?
Válasz
an enzyme optimum
249. kártya
Kérdés
Which term describes pathway control by inhibition from an end product?
Válasz
feedback inhibition
250. kártya
Kérdés
Why does each enzyme have a characteristic pH range?
Válasz
pH changes the ionization of amino-acid side chains, affecting active-site shape and chemical interactions.
251. kártya
Kérdés
Why does increasing substrate concentration eventually stop increasing enzyme rate?
Válasz
At saturation, nearly all active sites are occupied and enzyme concentration limits the maximum rate.
252. kártya
Kérdés
How does increasing enzyme concentration affect rate when substrate is abundant?
Válasz
More active sites are available, so the initial rate increases roughly in proportion to enzyme concentration.
253. kártya
Kérdés
What gives an enzyme substrate specificity?
Válasz
The active site's shape, charge, polarity, and chemical groups complement particular substrates and transition states.
254. kártya
Kérdés
What is one practical advantage of immobilizing an enzyme?
Válasz
The enzyme can be separated from products and reused while conditions around it are controlled.
255. kártya
Kérdés
Does an enzyme change a reaction's equilibrium position?
Válasz
No. It speeds forward and reverse reactions but does not change the equilibrium constant or final equilibrium position.
256. kártya
Kérdés
How can high substrate concentration reduce competitive inhibition?
Válasz
More substrate molecules increase the chance that substrate rather than inhibitor occupies the active site.
257. kártya
Kérdés
Why are metabolic reactions commonly organized into pathways?
Válasz
A sequence of enzyme-controlled steps allows energy changes and intermediates to be controlled and coupled.
258. kártya
Kérdés
What is ATP?
Válasz
A nucleotide that transfers usable energy through coupling of its hydrolysis to cellular processes.
259. kártya
Kérdés
What is cellular respiration?
Válasz
Controlled release of energy from organic molecules to produce ATP.
260. kártya
Kérdés
What is glycolysis?
Válasz
A cytosolic pathway that splits glucose into two pyruvate molecules and yields a small amount of ATP and reduced electron carriers.
261. kártya
Kérdés
What is pyruvate?
Válasz
The three-carbon product of glycolysis that can enter aerobic or anaerobic pathways.
262. kártya
Kérdés
Which term describes the cell's immediate phosphoryl-group energy carrier?
Válasz
ATP
263. kártya
Kérdés
Which term describes controlled ATP-producing breakdown of organic molecules?
Válasz
cellular respiration
264. kártya
Kérdés
Which term describes the cytosolic splitting of glucose into pyruvate?
Válasz
glycolysis
265. kártya
Kérdés
Which term describes the three-carbon product of glycolysis?
Válasz
pyruvate
266. kártya
Kérdés
What is aerobic respiration?
Válasz
Respiration that uses oxygen as the final electron acceptor and produces much more ATP than fermentation.
267. kártya
Kérdés
What is anaerobic metabolism?
Válasz
ATP-producing metabolism that proceeds without oxygen.
268. kártya
Kérdés
What is fermentation?
Válasz
An anaerobic pathway that regenerates oxidized electron carriers so glycolysis can continue.
269. kártya
Kérdés
What is oxidation?
Válasz
Loss of electrons, often accompanied in biology by loss of hydrogen or gain of oxygen.
270. kártya
Kérdés
Which term describes respiration using oxygen as final electron acceptor?
Válasz
aerobic respiration
271. kártya
Kérdés
Which term describes ATP-producing metabolism without oxygen?
Válasz
anaerobic metabolism
272. kártya
Kérdés
Which term describes anaerobic regeneration of electron carriers after glycolysis?
Válasz
fermentation
273. kártya
Kérdés
Which term describes loss of electrons?
Válasz
oxidation
274. kártya
Kérdés
What is reduction?
Válasz
Gain of electrons, often accompanied in biology by gain of hydrogen or loss of oxygen.
275. kártya
Kérdés
What is a reduced electron carrier?
Válasz
A molecule such as NADH that carries high-energy electrons and hydrogen from one reaction to another.
276. kártya
Kérdés
What is chemiosmosis?
Válasz
ATP production driven by ions moving down an electrochemical gradient through ATP synthase.
277. kártya
Kérdés
What is the overall word equation for aerobic respiration of glucose?
Válasz
Glucose + oxygen → carbon dioxide + water + energy transferred to ATP and heat.
278. kártya
Kérdés
Which term describes gain of electrons?
Válasz
reduction
279. kártya
Kérdés
Which term describes a molecule carrying high-energy electrons between reactions?
Válasz
a reduced electron carrier
280. kártya
Kérdés
Which term describes ATP production powered by an ion gradient?
Válasz
chemiosmosis
281. kártya
Kérdés
Where does glycolysis occur?
Válasz
In the cytosol.
282. kártya
Kérdés
What major stages of aerobic respiration occur in mitochondria?
Válasz
Pyruvate oxidation and the citric acid cycle occur in the matrix; electron transport and chemiosmosis occur at the inner membrane.
283. kártya
Kérdés
What is oxygen's direct role in aerobic respiration?
Válasz
It accepts electrons and hydrogen ions at the end of the electron transport chain, forming water.
284. kártya
Kérdés
Why does aerobic respiration yield much more ATP per glucose than fermentation?
Válasz
It transfers electrons through an electron transport chain and uses oxidative phosphorylation, extracting far more of glucose's energy.
285. kártya
Kérdés
What is the purpose of lactate formation in oxygen-limited animal cells?
Válasz
It regenerates NAD⁺ so glycolysis can continue producing a small amount of ATP.
286. kártya
Kérdés
What products are formed during alcoholic fermentation in yeast?
Válasz
Ethanol and carbon dioxide, while NAD⁺ is regenerated.
287. kártya
Kérdés
Why is some energy released by respiration transferred as heat rather than captured in ATP?
Válasz
Energy conversions are not fully efficient, so part of the chemical energy becomes disordered molecular motion.
288. kártya
Kérdés
What is substrate-level phosphorylation?
Válasz
Direct transfer of a phosphate group from a metabolic intermediate to ADP to form ATP.
289. kártya
Kérdés
How does electron transport lead to ATP synthesis in mitochondria?
Válasz
Electron energy pumps protons across the inner membrane; proton flow back through ATP synthase drives ATP formation.
290. kártya
Kérdés
Why can intense exercise increase lactate production?
Válasz
ATP demand can exceed oxygen delivery and aerobic capacity, so cells regenerate NAD⁺ through lactate formation to sustain glycolysis.
291. kártya
Kérdés
What is photosynthesis?
Válasz
Conversion of light energy into chemical energy used to synthesize organic molecules from carbon dioxide.
292. kártya
Kérdés
What is chlorophyll?
Válasz
A green pigment that absorbs light energy for photosynthesis.
293. kártya
Kérdés
What is an absorption spectrum?
Válasz
A graph showing how strongly a pigment absorbs different wavelengths of light.
294. kártya
Kérdés
What is an action spectrum?
Válasz
A graph showing the rate or effectiveness of photosynthesis at different wavelengths.
295. kártya
Kérdés
Which term describes light-driven synthesis of organic molecules from carbon dioxide?
Válasz
photosynthesis
296. kártya
Kérdés
Which term describes the principal green photosynthetic pigment?
Válasz
chlorophyll
297. kártya
Kérdés
Which term describes a graph of pigment absorption versus wavelength?
Válasz
an absorption spectrum
298. kártya
Kérdés
Which term describes a graph of photosynthetic effectiveness versus wavelength?
Válasz
an action spectrum
299. kártya
Kérdés
What is photolysis of water?
Válasz
Light-driven splitting of water that supplies electrons and hydrogen ions and releases oxygen.
300. kártya
Kérdés
What are light-dependent reactions?
Válasz
Photosynthetic reactions that use light to generate ATP and reduced electron carriers while releasing oxygen.
301. kártya
Kérdés
What is the Calvin cycle?
Válasz
A set of chloroplast reactions that uses ATP and reduced electron carriers to convert carbon dioxide into carbohydrate precursors.
302. kártya
Kérdés
What is carbon fixation?
Válasz
Incorporation of inorganic carbon dioxide into an organic molecule.
303. kártya
Kérdés
Which term describes light-driven splitting of water?
Válasz
photolysis of water
304. kártya
Kérdés
Which term describes photosynthetic reactions that directly capture light energy?
Válasz
light-dependent reactions
305. kártya
Kérdés
Which term describes the carbon-reduction cycle of photosynthesis?
Válasz
the Calvin cycle
306. kártya
Kérdés
Which term describes incorporation of carbon dioxide into organic matter?
Válasz
carbon fixation
307. kártya
Kérdés
What is the role of a stoma in photosynthesis?
Válasz
A pore in the leaf epidermis that regulates carbon-dioxide entry as well as water loss.
308. kártya
Kérdés
What is a limiting factor of photosynthesis?
Válasz
The environmental factor whose availability currently restricts the photosynthetic rate.
309. kártya
Kérdés
What is the light compensation point?
Válasz
The light intensity at which photosynthetic carbon uptake equals respiratory carbon release.
310. kártya
Kérdés
What is the overall word equation for oxygenic photosynthesis?
Válasz
Carbon dioxide + water → carbohydrate + oxygen, using light energy.
311. kártya
Kérdés
Which term describes the regulated leaf pore controlling carbon-dioxide entry for photosynthesis?
Válasz
a stoma
312. kártya
Kérdés
Which term describes the factor currently restricting photosynthetic rate?
Válasz
a limiting factor
313. kártya
Kérdés
Which term describes the light level where photosynthesis and respiration balance?
Válasz
the light compensation point
314. kártya
Kérdés
Where do the main stages of photosynthesis occur in a chloroplast?
Válasz
Light-dependent reactions occur in thylakoid membranes; carbon-fixation reactions occur in the stroma.
315. kártya
Kérdés
What energy conversion occurs during photosynthesis?
Válasz
Light energy is converted into chemical energy stored first in ATP and reduced carriers and ultimately in organic molecules.
316. kártya
Kérdés
From which reactant does the oxygen released by photosynthesis originate?
Válasz
Water.
317. kártya
Kérdés
What role does RuBisCO play in photosynthesis?
Válasz
It catalyzes fixation of carbon dioxide by adding it to an organic acceptor molecule.
318. kártya
Kérdés
What tradeoff is controlled when stomata open?
Válasz
Opening permits carbon dioxide entry but increases water loss by transpiration.
319. kártya
Kérdés
Name three leaf features that support photosynthesis.
Válasz
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. kártya
Kérdés
What can a plant do with carbohydrate made by photosynthesis?
Válasz
Use it in respiration, convert it to storage or structural carbohydrates, or use its carbon to make lipids, amino acids, and other molecules.
321. kártya
Kérdés
How are products of the light-dependent reactions used in carbon fixation?
Válasz
ATP supplies energy and NADPH supplies reducing power for conversion of fixed carbon into carbohydrate precursors.
322. kártya
Kérdés
Why does increasing light intensity eventually stop increasing photosynthetic rate?
Válasz
Another factor, such as carbon dioxide supply, temperature, or biochemical capacity, becomes limiting.
323. kártya
Kérdés
How can increasing carbon dioxide concentration affect photosynthetic rate?
Válasz
It can increase the rate until another factor becomes limiting.
324. kártya
Kérdés
Why does photosynthetic rate usually have a temperature optimum?
Válasz
Enzyme-controlled reactions accelerate with temperature up to an optimum, then decline as enzymes and membranes lose effective function.
325. kártya
Kérdés
Why does an action spectrum broadly resemble the combined absorption spectra of photosynthetic pigments?
Válasz
Wavelengths absorbed by the pigments supply more energy for photosynthesis than poorly absorbed wavelengths.
326. kártya
Kérdés
What is semiconservative replication?
Válasz
DNA replication in which each daughter molecule contains one parental strand and one newly synthesized strand.
327. kártya
Kérdés
What is DNA helicase?
Válasz
An enzyme that unwinds the double helix and separates the strands by disrupting base pairing.
328. kártya
Kérdés
What is DNA polymerase?
Válasz
An enzyme that adds nucleotides to a growing DNA strand using a template.
329. kártya
Kérdés
What is a primer?
Válasz
A short nucleic-acid segment providing a free 3′ end from which DNA polymerase can extend.
330. kártya
Kérdés
Which term describes replication producing one old and one new strand per DNA molecule?
Válasz
semiconservative replication
331. kártya
Kérdés
Which term describes the enzyme that separates DNA strands?
Válasz
DNA helicase
332. kártya
Kérdés
Which term describes the enzyme that builds DNA from a template?
Válasz
DNA polymerase
333. kártya
Kérdés
Which term describes the short segment providing a starting 3′ end?
Válasz
a primer
334. kártya
Kérdés
What is the leading strand?
Válasz
The new DNA strand synthesized continuously toward the replication fork.
335. kártya
Kérdés
What is the lagging strand?
Válasz
The new DNA strand synthesized discontinuously away from the replication fork.
336. kártya
Kérdés
What is an Okazaki fragment?
Válasz
A short DNA segment synthesized on the lagging strand.
337. kártya
Kérdés
What is DNA ligase?
Válasz
An enzyme that seals breaks in the sugar-phosphate backbone, joining DNA fragments.
338. kártya
Kérdés
Which term describes the continuously synthesized daughter strand?
Válasz
the leading strand
339. kártya
Kérdés
Which term describes the discontinuously synthesized daughter strand?
Válasz
the lagging strand
340. kártya
Kérdés
Which term describes a short newly made segment of lagging-strand DNA?
Válasz
an Okazaki fragment
341. kártya
Kérdés
Which term describes the enzyme that joins DNA fragments by sealing the backbone?
Válasz
DNA ligase
342. kártya
Kérdés
How does complementary base pairing ensure accurate DNA copying?
Válasz
Each template base specifies the nucleotide added opposite it: A pairs with T, and C pairs with G.
343. kártya
Kérdés
Why does DNA polymerase synthesize DNA only 5′ to 3′?
Válasz
It can add a nucleotide only to the free 3′ hydroxyl group of the growing strand.
344. kártya
Kérdés
When in the cell cycle is nuclear DNA replicated?
Válasz
During S phase of interphase, before cell division.
345. kártya
Kérdés
How can a replication error become a permanent mutation?
Válasz
If it escapes proofreading and repair, the altered sequence can be copied in later cell generations.
346. kártya
Kérdés
Why are leading and lagging strands synthesized differently?
Válasz
The templates are antiparallel while DNA polymerase works only 5′ to 3′, forcing one strand to be made discontinuously.
347. kártya
Kérdés
How do proofreading and repair reduce replication errors?
Válasz
Incorrectly paired nucleotides are recognized, removed, and replaced before or after replication continues.
348. kártya
Kérdés
What three repeating steps amplify DNA in PCR?
Válasz
Strand separation by heating, primer annealing during cooling, and DNA extension by a heat-stable polymerase.
349. kártya
Kérdés
What determines which DNA region PCR amplifies?
Válasz
The sequences and positions of the two primers flanking the target region.
350. kártya
Kérdés
What is transcription?
Válasz
Synthesis of RNA from a DNA template.
351. kártya
Kérdés
What is RNA polymerase?
Válasz
The enzyme that synthesizes RNA complementary to a DNA template strand.
352. kártya
Kérdés
What is messenger RNA?
Válasz
RNA carrying a coding sequence from DNA to ribosomes.
353. kártya
Kérdés
What is a codon?
Válasz
A three-base sequence in mRNA that specifies an amino acid or a translation signal.
354. kártya
Kérdés
Which term describes RNA synthesis from DNA?
Válasz
transcription
355. kártya
Kérdés
Which term describes the enzyme that builds RNA from a DNA template?
Válasz
RNA polymerase
356. kártya
Kérdés
Which term describes RNA that carries coding information to ribosomes?
Válasz
messenger RNA
357. kártya
Kérdés
Which term describes a three-base mRNA unit?
Válasz
a codon
358. kártya
Kérdés
What is translation?
Válasz
Synthesis of a polypeptide using the codon sequence of mRNA.
359. kártya
Kérdés
What does a ribosome do during translation?
Válasz
It reads mRNA and catalyzes polypeptide synthesis using its rRNA-protein machinery.
360. kártya
Kérdés
What is transfer RNA?
Válasz
RNA that carries a specific amino acid and pairs its anticodon with an mRNA codon.
361. kártya
Kérdés
What is an anticodon?
Válasz
A three-base tRNA sequence complementary to an mRNA codon.
362. kártya
Kérdés
Which term describes polypeptide synthesis from an mRNA sequence?
Válasz
translation
363. kártya
Kérdés
Which term describes the translation complex that reads mRNA and builds a polypeptide?
Válasz
a ribosome
364. kártya
Kérdés
Which term describes the adaptor RNA carrying an amino acid?
Válasz
transfer RNA
365. kártya
Kérdés
Which term describes the tRNA triplet that pairs with a codon?
Válasz
an anticodon
366. kártya
Kérdés
What is the genetic code?
Válasz
The set of rules relating mRNA codons to amino acids and translation signals.
367. kártya
Kérdés
What are start and stop codons?
Válasz
mRNA signals that establish the reading frame or terminate translation.
368. kártya
Kérdés
Where do transcription and translation occur in a eukaryotic cell?
Válasz
Transcription occurs in the nucleus; translation occurs on ribosomes in the cytoplasm or on rough ER.
369. kártya
Kérdés
How is an mRNA sequence related to its DNA template strand?
Válasz
It is complementary and antiparallel, with uracil in RNA opposite adenine in DNA.
370. kártya
Kérdés
Which term describes the codon-to-amino-acid rule set?
Válasz
the genetic code
371. kártya
Kérdés
Which term describes codons that begin or end translation?
Válasz
start and stop codons
372. kártya
Kérdés
What reaction does the ribosome catalyze as a polypeptide grows?
Válasz
Formation of peptide bonds between adjacent amino acids.
373. kártya
Kérdés
What does it mean that the genetic code is degenerate?
Válasz
Most amino acids are specified by more than one codon.
374. kártya
Kérdés
How can one mRNA produce many polypeptides quickly?
Válasz
Multiple ribosomes can translate the same mRNA simultaneously as a polyribosome.
375. kártya
Kérdés
Why is translation not the final step in producing many functional proteins?
Válasz
The polypeptide must fold and may undergo cleavage, chemical modification, or assembly with other subunits.
376. kártya
Kérdés
How does mRNA compare with the DNA coding strand?
Válasz
It has the same base sequence except that RNA contains uracil where DNA contains thymine.
377. kártya
Kérdés
What happens during eukaryotic RNA splicing?
Válasz
Introns are removed and exons are joined to form mature mRNA.
378. kártya
Kérdés
Why must codons be read in the correct reading frame?
Válasz
Changing the starting position changes every downstream triplet and therefore the amino-acid sequence.
379. kártya
Kérdés
How is the correct amino acid matched to each mRNA codon?
Válasz
Each tRNA is charged with a particular amino acid, and its anticodon pairs with the complementary codon.
380. kártya
Kérdés
How can a base substitution affect a protein?
Válasz
It may be silent, change one amino acid, create a stop codon, or sometimes alter RNA processing.
381. kártya
Kérdés
What is a mutation?
Válasz
A change in a DNA sequence or chromosome structure that can be passed to daughter cells.
382. kártya
Kérdés
What is a base substitution?
Válasz
Replacement of one nucleotide pair by another.
383. kártya
Kérdés
What is an insertion mutation?
Válasz
Addition of one or more nucleotides to a DNA sequence.
384. kártya
Kérdés
What is a deletion mutation?
Válasz
Loss of one or more nucleotides from a DNA sequence.
385. kártya
Kérdés
Which term describes a lasting DNA-sequence or chromosome change?
Válasz
a mutation
386. kártya
Kérdés
Which term describes replacement of one DNA base pair?
Válasz
a base substitution
387. kártya
Kérdés
Which term describes addition of nucleotides to DNA?
Válasz
an insertion mutation
388. kártya
Kérdés
Which term describes loss of nucleotides from DNA?
Válasz
a deletion mutation
389. kártya
Kérdés
What is a frameshift mutation?
Válasz
A coding-sequence insertion or deletion not divisible by three that changes downstream codon grouping.
390. kártya
Kérdés
What is a silent mutation?
Válasz
A sequence change that does not alter the encoded amino acid.
391. kártya
Kérdés
What is a missense mutation?
Válasz
A mutation that changes a codon so a different amino acid is incorporated.
392. kártya
Kérdés
What is a nonsense mutation?
Válasz
A mutation that changes an amino-acid codon into a stop codon.
393. kártya
Kérdés
Which term describes a mutation that shifts downstream codon grouping?
Válasz
a frameshift mutation
394. kártya
Kérdés
Which term describes a coding change that leaves the amino acid unchanged?
Válasz
a silent mutation
395. kártya
Kérdés
Which term describes a mutation causing one amino-acid substitution?
Válasz
a missense mutation
396. kártya
Kérdés
Which term describes a mutation creating a premature stop codon?
Válasz
a nonsense mutation
397. kártya
Kérdés
How do germline and somatic mutations differ in inheritance?
Válasz
Germline mutations can enter gametes and be inherited; somatic mutations affect a cell lineage within the individual.
398. kártya
Kérdés
What can cause mutations?
Válasz
Replication errors, spontaneous chemical changes, radiation, and mutagenic chemicals can alter DNA.
399. kártya
Kérdés
How does DNA repair protect genome stability?
Válasz
Repair systems detect damaged or mismatched DNA and restore the correct structure or sequence when possible.
400. kártya
Kérdés
Why are mutations essential to evolution despite often being neutral or harmful?
Válasz
They create new alleles, providing the heritable variation on which selection and drift act.
401. kártya
Kérdés
What is the basic role of guide RNA in CRISPR gene editing?
Válasz
It directs a nuclease to a complementary DNA sequence.
402. kártya
Kérdés
Why can the same type of DNA mutation have effects ranging from none to severe?
Válasz
Effects depend on location, genetic-code redundancy, protein role, cell type, and environmental context.
403. kártya
Kérdés
How can accumulated mutations contribute to cancer?
Válasz
Mutations can activate growth-promoting genes or disable genes that restrain division, repair DNA, or trigger cell death.
404. kártya
Kérdés
Why can repairing a CRISPR-induced DNA break produce different editing outcomes?
Válasz
Different cellular repair pathways may disrupt the target sequence or use a supplied template for a specific change.
405. kártya
Kérdés
What is an off-target effect in gene editing?
Válasz
An unintended DNA change at a site sufficiently similar to the intended target.
406. kártya
Kérdés
Why does heritable human genome editing raise additional ethical concerns?
Válasz
Changes could pass to future generations who cannot consent, with uncertain long-term biological and social effects.
407. kártya
Kérdés
What is the cell cycle?
Válasz
The ordered sequence of cell growth, DNA replication, nuclear division, and cell division.
408. kártya
Kérdés
What is interphase?
Válasz
The period of growth, normal activity, and DNA replication between nuclear divisions.
409. kártya
Kérdés
What is mitosis?
Válasz
Nuclear division that usually produces genetically equivalent daughter nuclei.
410. kártya
Kérdés
What is cytokinesis?
Válasz
Division of the cytoplasm to form separate daughter cells.
411. kártya
Kérdés
Which term describes the ordered sequence from one cell division to the next?
Válasz
the cell cycle
412. kártya
Kérdés
Which term describes the growth and DNA-replication period between divisions?
Válasz
interphase
413. kártya
Kérdés
Which term describes division producing genetically equivalent nuclei?
Válasz
mitosis
414. kártya
Kérdés
Which term describes physical division of the cytoplasm?
Válasz
cytokinesis
415. kártya
Kérdés
What is a chromosome?
Válasz
One DNA molecule packaged with associated proteins.
416. kártya
Kérdés
What are sister chromatids?
Válasz
The two replicated copies of a chromosome joined before separation.
417. kártya
Kérdés
What is a centromere?
Válasz
The chromosome region that holds sister chromatids together and organizes kinetochore attachment.
418. kártya
Kérdés
What is the mitotic spindle?
Válasz
A microtubule system that attaches to and separates chromosomes during cell division.
419. kártya
Kérdés
Which term describes a protein-packaged DNA molecule?
Válasz
a chromosome
420. kártya
Kérdés
Which term describes joined replicated copies of one chromosome?
Válasz
sister chromatids
421. kártya
Kérdés
Which term describes the chromosome region joining sister chromatids?
Válasz
a centromere
422. kártya
Kérdés
Which term describes the chromosome-separating microtubule system?
Válasz
the mitotic spindle
423. kártya
Kérdés
What is the basic sequence of mitosis?
Válasz
Chromosomes condense, align at the cell equator, sister chromatids separate to opposite poles, and new nuclei form.
424. kártya
Kérdés
Why must DNA replicate before mitosis?
Válasz
Each chromosome must have two copies so each daughter nucleus can receive a complete genome.
425. kártya
Kérdés
Why are daughter cells from mitosis usually genetically similar?
Válasz
Replicated sister chromatids are separated so each daughter receives one copy of every chromosome.
426. kártya
Kérdés
What are major roles of mitosis in multicellular organisms?
Válasz
Growth, tissue repair, cell replacement, and some forms of asexual reproduction.
427. kártya
Kérdés
How do homologous chromosomes differ from sister chromatids?
Válasz
Homologs carry the same gene loci but may have different alleles; sister chromatids are replicated copies of one chromosome.
428. kártya
Kérdés
What key outcome distinguishes mitosis from meiosis?
Válasz
Mitosis usually preserves chromosome number and similarity; meiosis halves chromosome number and generates genetically varied haploid cells.
429. kártya
Kérdés
How does cytokinesis commonly occur in animal cells?
Válasz
A contractile ring tightens the plasma membrane into a cleavage furrow.
430. kártya
Kérdés
How does cytokinesis commonly occur in plant cells?
Válasz
Vesicles fuse at the center to form a cell plate that develops into new membranes and a cell wall.
431. kártya
Kérdés
What is the purpose of cell-cycle checkpoints?
Válasz
They delay progression when conditions are unsuitable or DNA and chromosome attachment are defective.
432. kártya
Kérdés
How is loss of cell-cycle control related to cancer?
Válasz
Cells can divide despite damage or growth restraints, producing an expanding abnormal clone.
433. kártya
Kérdés
What is a gene?
Válasz
A DNA sequence that contributes to a functional product and influences a characteristic or cellular process.
434. kártya
Kérdés
What is an allele?
Válasz
One of the alternative DNA-sequence forms at a gene locus.
435. kártya
Kérdés
What is a gene locus?
Válasz
The physical position of a gene on a chromosome.
436. kártya
Kérdés
What is a genotype?
Válasz
The allele combination of an organism at one or more loci.
437. kártya
Kérdés
Which term describes a functional DNA sequence?
Válasz
a gene
438. kártya
Kérdés
Which term describes an alternative form of a gene?
Válasz
an allele
439. kártya
Kérdés
Which term describes a gene's chromosome position?
Válasz
a gene locus
440. kártya
Kérdés
Which term describes an organism's allele combination?
Válasz
a genotype
441. kártya
Kérdés
What is a phenotype?
Válasz
An observable or measurable trait produced by genotype and environment.
442. kártya
Kérdés
What is homozygous?
Válasz
Having two identical alleles at a diploid locus.
443. kártya
Kérdés
What is heterozygous?
Válasz
Having two different alleles at a diploid locus.
444. kártya
Kérdés
What is a dominant allele?
Válasz
An allele expressed in the phenotype of a heterozygote under a specified inheritance model.
445. kártya
Kérdés
Which term describes an observable trait resulting from genes and environment?
Válasz
a phenotype
446. kártya
Kérdés
Which term describes having two identical alleles at a locus?
Válasz
homozygous
447. kártya
Kérdés
Which term describes having two different alleles at a locus?
Válasz
heterozygous
448. kártya
Kérdés
Which term describes an allele expressed in a heterozygote?
Válasz
a dominant allele
449. kártya
Kérdés
What is a recessive allele?
Válasz
An allele whose phenotype is masked by a dominant allele in a heterozygote.
450. kártya
Kérdés
What is a genetic carrier?
Válasz
An unaffected heterozygote who can transmit a recessive disease allele.
451. kártya
Kérdés
What is a test cross?
Válasz
A cross with a homozygous recessive individual used to infer an unknown dominant phenotype's genotype.
452. kártya
Kérdés
What is a pedigree?
Válasz
A diagram showing biological relationships and occurrence of a trait across generations.
453. kártya
Kérdés
Which term describes an allele masked in a heterozygote?
Válasz
a recessive allele
454. kártya
Kérdés
Which term describes an unaffected heterozygote carrying a recessive disease allele?
Válasz
a genetic carrier
455. kártya
Kérdés
Which term describes a cross used to reveal an unknown dominant genotype?
Válasz
a test cross
456. kártya
Kérdés
Which term describes a family diagram tracking a trait across generations?
Válasz
a pedigree
457. kártya
Kérdés
What does allele segregation mean during gamete formation?
Válasz
The two alleles at a diploid locus separate so each gamete receives one.
458. kártya
Kérdés
What does a Punnett square predict?
Válasz
Expected genotype and phenotype probabilities from specified parental gametes, not guaranteed family outcomes.
459. kártya
Kérdés
What phenotypic ratio is expected from Aa × Aa with complete dominance?
Válasz
Approximately 3 dominant phenotype : 1 recessive phenotype.
460. kártya
Kérdés
What genotypic ratio is expected from Aa × Aa?
Válasz
1 AA : 2 Aa : 1 aa.
461. kártya
Kérdés
What happens in codominance?
Válasz
Both alleles contribute distinctly to the heterozygous phenotype.
462. kártya
Kérdés
What happens in incomplete dominance?
Válasz
The heterozygote has a phenotype intermediate between the two homozygotes.
463. kártya
Kérdés
How can environment affect phenotype without changing genotype?
Válasz
Conditions alter development, physiology, or gene expression, changing the observed trait.
464. kártya
Kérdés
What is the ultimate source of new alleles?
Válasz
Mutation.
465. kártya
Kérdés
Why are X-linked recessive traits more common in XY individuals?
Válasz
They have only one X chromosome, so one recessive allele on it can determine the phenotype.
466. kártya
Kérdés
When is the product rule used in genetic probability?
Válasz
For independent events that must both occur; multiply their probabilities.
467. kártya
Kérdés
When is the sum rule used in genetic probability?
Válasz
For mutually exclusive alternative outcomes; add their probabilities.
468. kártya
Kérdés
Why do polygenic traits often show continuous variation?
Válasz
Many loci contribute small effects, creating many possible genotypes and phenotypes, often further influenced by environment.
469. kártya
Kérdés
What pedigree pattern can suggest an autosomal recessive trait?
Válasz
Unaffected parents can have affected children, and all sexes are affected at similar frequencies.
470. kártya
Kérdés
What is a species?
Válasz
A group of organisms whose members can potentially interbreed and produce fertile offspring under natural conditions.
471. kártya
Kérdés
What is binomial nomenclature?
Válasz
The two-part scientific naming system using a genus name followed by a specific epithet.
472. kártya
Kérdés
What is taxonomy?
Válasz
The naming and classification of organisms.
473. kártya
Kérdés
What is a biological domain?
Válasz
The broadest commonly used taxonomic rank, separating Bacteria, Archaea, and Eukarya.
474. kártya
Kérdés
Which term describes a naturally interbreeding group producing fertile offspring?
Válasz
a species
475. kártya
Kérdés
Which term describes the genus-plus-specific-epithet naming system?
Válasz
binomial nomenclature
476. kártya
Kérdés
Which term describes the science of naming and classifying organisms?
Válasz
taxonomy
477. kártya
Kérdés
Which term describes the broadest common taxonomic rank?
Válasz
a biological domain
478. kártya
Kérdés
What is biodiversity?
Válasz
Variation of life at genetic, species, and ecosystem levels.
479. kártya
Kérdés
What is an autotroph?
Válasz
An organism that makes organic compounds from inorganic carbon using light or chemical energy.
480. kártya
Kérdés
What is a heterotroph?
Válasz
An organism that obtains organic carbon by consuming other organisms or their products.
960 kártya
IB Biology SL Flashcards: Complete Course Review
Tanulj ingyen ebből a paklibólA Nibomo megnyílik, és elkezdheted a tanulást.
481. kártya
Kérdés
What is a unicellular organism?
Válasz
An organism consisting of one cell that carries out all essential life functions.
482. kártya
Kérdés
Which term describes variation of life across genes, species, and ecosystems?
Válasz
biodiversity
483. kártya
Kérdés
Which term describes an organism that builds organic matter from inorganic carbon?
Válasz
an autotroph
484. kártya
Kérdés
Which term describes an organism obtaining organic carbon from other organisms?
Válasz
a heterotroph
485. kártya
Kérdés
Which term describes an organism made of one cell?
Válasz
a unicellular organism
486. kártya
Kérdés
What is a multicellular organism?
Válasz
An organism composed of many cooperating cells, often with specialized cell types.
487. kártya
Kérdés
What is a karyotype?
Válasz
An ordered display of chromosomes used to examine their number and large-scale structure.
488. kártya
Kérdés
What broad feature distinguishes both Bacteria and Archaea from Eukarya?
Válasz
Their cells lack a nucleus and other membrane-bound organelles.
489. kártya
Kérdés
What features characterize most plant cells?
Válasz
Cellulose walls, chloroplasts in photosynthetic tissues, and large vacuoles are typical features.
490. kártya
Kérdés
Which term describes an organism made of many cooperating cells?
Válasz
a multicellular organism
491. kártya
Kérdés
Which term describes an ordered display of an individual's chromosomes?
Válasz
a karyotype
492. kártya
Kérdés
How do fungi obtain nutrients?
Válasz
They secrete digestive enzymes and absorb soluble products; their cells usually have chitin-containing walls.
493. kártya
Kérdés
What distinguishes animal nutrition and cell structure?
Válasz
Animals ingest organic material, and their cells lack cell walls and chloroplasts.
494. kártya
Kérdés
Why are scientific names useful across languages?
Válasz
A standardized name identifies the same organism internationally and reduces ambiguity from local common names.
495. kártya
Kérdés
Why can genetic diversity improve a population's resilience?
Válasz
More heritable variation increases the chance that some individuals tolerate new diseases or environmental changes.
496. kártya
Kérdés
What does ecosystem diversity measure?
Válasz
The variety of habitats, communities, and ecological processes within a region.
497. kártya
Kérdés
Why are Archaea classified separately from Bacteria?
Válasz
They differ in genetic sequences, membrane chemistry, cell-wall composition, and aspects of molecular machinery.
498. kártya
Kérdés
Why is the biological species concept difficult to apply to fossils or asexual organisms?
Válasz
Their ability to interbreed and produce fertile offspring cannot be tested in the usual way.
499. kártya
Kérdés
Does a larger chromosome number necessarily mean a more complex organism?
Válasz
No. Chromosome number varies through fusion, fission, and duplication and does not directly measure biological complexity.
500. kártya
Kérdés
Does genome size reliably predict organismal complexity?
Válasz
No. Large amounts of noncoding and repeated DNA make genome size a poor simple measure of complexity.
501. kártya
Kérdés
What evidence can be combined when classifying organisms?
Válasz
Molecular sequences, cell structure, anatomy, development, physiology, and reproductive evidence can all contribute.
502. kártya
Kérdés
What is gas exchange?
Válasz
Diffusion of respiratory gases between an organism and its environment or transport fluid.
503. kártya
Kérdés
What is ventilation?
Válasz
Bulk movement of air or water over a gas-exchange surface.
504. kártya
Kérdés
What is an alveolus?
Válasz
A microscopic air sac in the lung where gases diffuse between air and blood.
505. kártya
Kérdés
What is pulmonary surfactant?
Válasz
A substance lining alveoli that lowers surface tension and reduces collapse.
506. kártya
Kérdés
Which term describes diffusion of oxygen and carbon dioxide across a respiratory surface?
Válasz
gas exchange
507. kártya
Kérdés
Which term describes bulk movement of respiratory medium over an exchange surface?
Válasz
ventilation
508. kártya
Kérdés
Which term describes a microscopic lung air sac?
Válasz
an alveolus
509. kártya
Kérdés
Which term describes the alveolar lining that lowers surface tension?
Válasz
pulmonary surfactant
510. kártya
Kérdés
What is the diaphragm?
Válasz
A sheet of skeletal muscle whose contraction increases thoracic volume during inhalation.
511. kártya
Kérdés
What is tidal volume?
Válasz
The volume of air moved in or out during a normal breath.
512. kártya
Kérdés
What is a stoma?
Válasz
A regulated epidermal pore through which gases diffuse in leaves.
513. kártya
Kérdés
What is countercurrent exchange?
Válasz
Exchange between fluids moving in opposite directions, maintaining a gradient along most of the surface.
514. kártya
Kérdés
Which term describes the muscle sheet that expands the thorax during inhalation?
Válasz
the diaphragm
515. kártya
Kérdés
Which term describes air volume moved in one normal breath?
Válasz
tidal volume
516. kártya
Kérdés
Which term describes a regulated leaf gas-exchange pore?
Válasz
a stoma
517. kártya
Kérdés
Which term describes opposite fluid flow that maintains an exchange gradient?
Válasz
countercurrent exchange
518. kártya
Kérdés
What features make an efficient gas-exchange surface?
Válasz
Large area, short diffusion distance, permeability, and maintained concentration gradients.
519. kártya
Kérdés
How is a steep oxygen gradient maintained across alveoli?
Válasz
Ventilation replenishes alveolar oxygen and blood flow removes absorbed oxygen.
520. kártya
Kérdés
How does diaphragm contraction cause inhalation?
Válasz
Thoracic volume increases, lung pressure falls below atmospheric pressure, and air flows inward.
521. kártya
Kérdés
What drives quiet exhalation?
Válasz
The diaphragm relaxes and elastic recoil reduces thoracic and lung volume, raising pressure and pushing air out.
522. kártya
Kérdés
Why do ventilation rate and depth increase during exercise?
Válasz
They increase oxygen uptake and carbon dioxide removal to support higher cellular respiration.
523. kártya
Kérdés
How does leaf structure shorten the pathway for carbon dioxide diffusion?
Válasz
Stomata open into air spaces, and mesophyll cells expose moist surfaces close to those spaces.
524. kártya
Kérdés
Why does carbon dioxide diffuse from tissues into blood?
Válasz
Respiring cells produce carbon dioxide, making its partial pressure higher in tissues than in incoming blood.
525. kártya
Kérdés
How does countercurrent flow improve oxygen uptake at fish gills?
Válasz
Blood continually meets water with a higher oxygen concentration, preserving diffusion along the lamella.
526. kártya
Kérdés
Why does closing stomata reduce both water loss and photosynthesis?
Válasz
It limits water-vapor diffusion out but also restricts carbon dioxide diffusion into the leaf.
527. kártya
Kérdés
What is a circulatory system?
Válasz
A transport system that moves a fluid carrying gases, nutrients, wastes, hormones, and heat through an organism.
528. kártya
Kérdés
What is an artery?
Válasz
A blood vessel carrying blood away from the heart under relatively high pressure.
529. kártya
Kérdés
What is a vein?
Válasz
A blood vessel carrying blood toward the heart, usually with low pressure and often valves.
530. kártya
Kérdés
What is a capillary?
Válasz
A microscopic thin-walled vessel where substances exchange between blood and tissues.
531. kártya
Kérdés
Which term describes an internal fluid-transport system?
Válasz
a circulatory system
532. kártya
Kérdés
Which term describes a vessel carrying blood away from the heart?
Válasz
an artery
533. kártya
Kérdés
Which term describes a vessel carrying blood toward the heart?
Válasz
a vein
534. kártya
Kérdés
Which term describes a microscopic exchange blood vessel?
Válasz
a capillary
535. kártya
Kérdés
What is the cardiac cycle?
Válasz
The repeating sequence of heart-chamber contraction and relaxation that pumps blood.
536. kártya
Kérdés
What is hemoglobin?
Válasz
An iron-containing protein in red blood cells that binds oxygen reversibly.
537. kártya
Kérdés
What is xylem?
Válasz
Plant vascular tissue that transports water and mineral ions and provides structural support.
538. kártya
Kérdés
What is phloem?
Válasz
Plant vascular tissue that transports sucrose and other organic solutes between sources and sinks.
539. kártya
Kérdés
Which term describes the repeating pumping sequence of the heart?
Válasz
the cardiac cycle
540. kártya
Kérdés
Which term describes the oxygen-carrying protein of red blood cells?
Válasz
hemoglobin
541. kártya
Kérdés
Which term describes plant tissue carrying water and minerals?
Válasz
xylem
542. kártya
Kérdés
Which term describes plant tissue carrying organic solutes?
Válasz
phloem
543. kártya
Kérdés
What is transpiration?
Válasz
Loss of water vapor from plant surfaces, mainly through stomata.
544. kártya
Kérdés
What is phloem translocation?
Válasz
Movement of organic solutes through phloem from sources to sinks.
545. kártya
Kérdés
How do a source and a sink differ in plant transport?
Válasz
A source releases assimilates to phloem; a sink removes them for use or storage.
546. kártya
Kérdés
What makes human circulation a double circulation?
Válasz
Blood passes through the heart once in the pulmonary circuit and again in the systemic circuit during one complete journey.
547. kártya
Kérdés
Which term describes water-vapor loss from plant surfaces?
Válasz
transpiration
548. kártya
Kérdés
Which term describes movement of organic solutes through phloem?
Válasz
phloem translocation
549. kártya
Kérdés
Which term describes the exporting and importing regions of phloem transport?
Válasz
source and sink
550. kártya
Kérdés
How is an artery adapted to high pressure?
Válasz
It has thick elastic and muscular walls and a relatively narrow lumen.
551. kártya
Kérdés
How is a vein adapted to return low-pressure blood?
Válasz
It has a wide lumen, thinner walls, and valves that reduce backflow.
552. kártya
Kérdés
How does capillary structure support exchange?
Válasz
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. kártya
Kérdés
What determines whether a heart valve opens or closes?
Válasz
Pressure differences across the valve.
554. kártya
Kérdés
Trace water from soil to the atmosphere through a plant.
Válasz
Soil → root hairs → root tissues → xylem → leaf mesophyll → leaf air spaces → stomata → atmosphere.
555. kártya
Kérdés
Why may root cells use active transport to absorb mineral ions?
Válasz
Ion concentrations can be lower in soil than in root cells, so uptake must occur against a gradient.
556. kártya
Kérdés
Why do large multicellular organisms need bulk transport systems?
Válasz
Their low surface-area-to-volume ratio and long diffusion distances make diffusion alone too slow for whole-body supply.
557. kártya
Kérdés
Why does hemoglobin unload more oxygen in actively respiring tissues?
Válasz
Lower oxygen and often higher carbon dioxide and acidity reduce hemoglobin's oxygen affinity.
558. kártya
Kérdés
How does transpiration pull water upward through xylem?
Válasz
Evaporation lowers leaf water potential and creates tension; cohesion transmits the pull through the continuous water column.
559. kártya
Kérdés
How do wind and low humidity generally affect transpiration?
Válasz
Both maintain a steep water-vapor gradient outside the leaf, increasing transpiration if stomata remain open.
560. kártya
Kérdés
What drives mass flow in phloem?
Válasz
Sugar loading draws in water and raises pressure at a source; unloading lowers pressure at a sink, producing bulk flow.
561. kártya
Kérdés
Can the same plant organ be a source at one time and a sink at another?
Válasz
Yes. A storage organ may import sugars while filling and export them later during growth or germination.
562. kártya
Kérdés
What is a neuron?
Válasz
An excitable cell specialized to receive, process, and transmit information.
563. kártya
Kérdés
What is a sensory neuron?
Válasz
A neuron carrying information from a receptor toward the central nervous system.
564. kártya
Kérdés
What is a motor neuron?
Válasz
A neuron carrying commands from the central nervous system to an effector.
565. kártya
Kérdés
What is the resting potential?
Válasz
The voltage difference across an unstimulated neuron's membrane, with the inside negative relative to outside.
566. kártya
Kérdés
Which term describes an excitable information-transmitting cell?
Válasz
a neuron
567. kártya
Kérdés
Which term describes a neuron carrying receptor information to the CNS?
Válasz
a sensory neuron
568. kártya
Kérdés
Which term describes a neuron carrying CNS commands to an effector?
Válasz
a motor neuron
569. kártya
Kérdés
Which term describes the negative-inside voltage of an unstimulated neuron?
Válasz
the resting potential
570. kártya
Kérdés
What is an action potential?
Válasz
A brief, self-propagating reversal and restoration of membrane potential along an excitable membrane.
571. kártya
Kérdés
What is depolarization?
Válasz
A change that makes membrane potential less negative, and during an action potential often positive.
572. kártya
Kérdés
What is repolarization?
Válasz
Return of membrane potential toward its resting negative value after depolarization.
573. kártya
Kérdés
What is a synapse?
Válasz
A junction where one cell communicates with another cell.
574. kártya
Kérdés
Which term describes a brief propagating change in neuron membrane voltage?
Válasz
an action potential
575. kártya
Kérdés
Which term describes a membrane-voltage change toward a less negative value?
Válasz
depolarization
576. kártya
Kérdés
Which term describes return toward resting membrane voltage?
Válasz
repolarization
577. kártya
Kérdés
Which term describes a communication junction between cells?
Válasz
a synapse
578. kártya
Kérdés
What is a neurotransmitter?
Válasz
A chemical released by a neuron that changes the activity of a target cell.
579. kártya
Kérdés
What is the refractory period?
Válasz
A brief period after an action potential when another is impossible or requires a stronger stimulus.
580. kártya
Kérdés
What is myelin?
Válasz
An insulating sheath around some axons that speeds impulse conduction.
581. kártya
Kérdés
What happens when membrane depolarization reaches threshold?
Válasz
Voltage-gated channels trigger the self-amplifying events of an action potential.
582. kártya
Kérdés
Which term describes a neuron-released signaling chemical?
Válasz
a neurotransmitter
583. kártya
Kérdés
Which term describes the recovery interval after an action potential?
Válasz
the refractory period
584. kártya
Kérdés
Which term describes the insulating axon sheath?
Válasz
myelin
585. kártya
Kérdés
What does the all-or-none principle mean for an action potential?
Válasz
Once threshold is reached, the action potential has a characteristic size; stronger stimuli increase frequency, not its amplitude.
586. kártya
Kérdés
How does myelin increase conduction speed?
Válasz
Depolarizing current travels rapidly beneath myelin and action potentials regenerate mainly at gaps in the sheath.
587. kártya
Kérdés
What is the basic sequence at a chemical synapse?
Válasz
An impulse triggers neurotransmitter release; it diffuses across the cleft, binds receptors, and alters the postsynaptic cell.
588. kártya
Kérdés
Why can a reflex response be rapid?
Válasz
A short neural pathway produces an automatic response without waiting for conscious processing.
589. kártya
Kérdés
What is sensory transduction?
Válasz
Conversion of a physical or chemical stimulus into an electrical signal in a receptor cell.
590. kártya
Kérdés
How does an action potential propagate along an axon?
Válasz
Local current depolarizes the next membrane region to threshold, opening voltage-gated channels there.
591. kártya
Kérdés
Why does an action potential normally travel in one direction along an axon?
Válasz
The membrane just behind it is refractory and cannot immediately fire again.
592. kártya
Kérdés
How is neurotransmitter action ended?
Válasz
The transmitter is removed by enzymatic breakdown, reuptake, or diffusion away.
593. kártya
Kérdés
What is sensory adaptation?
Válasz
Reduced receptor or neural response during a constant, unchanging stimulus.
594. kártya
Kérdés
How can a drug alter synaptic transmission?
Válasz
It may mimic or block a transmitter, change its release, or change its removal from the synaptic cleft.
595. kártya
Kérdés
What is an organ system?
Válasz
A group of organs coordinating to perform major functions for an organism.
596. kártya
Kérdés
What is a hormone?
Válasz
A signaling molecule released into transport fluid and acting on target cells with suitable receptors.
597. kártya
Kérdés
What is an endocrine gland?
Válasz
A gland that secretes hormones into extracellular fluid and blood rather than through a duct.
598. kártya
Kérdés
What is a hormone target cell?
Válasz
A cell able to respond because it has the appropriate receptor.
599. kártya
Kérdés
Which term describes a coordinated group of organs?
Válasz
an organ system
600. kártya
Kérdés
Which term describes a long-distance chemical messenger carried in body fluid?
Válasz
a hormone
601. kártya
Kérdés
Which term describes a ductless hormone-secreting gland?
Válasz
an endocrine gland
602. kártya
Kérdés
Which term describes a cell with a receptor for a particular hormone?
Válasz
a hormone target cell
603. kártya
Kérdés
What is digestion?
Válasz
Mechanical and chemical breakdown of food into molecules small enough to absorb.
604. kártya
Kérdés
What is absorption?
Válasz
Movement of digested nutrients across an exchange surface into blood or lymph.
605. kártya
Kérdés
What is peristalsis?
Válasz
Coordinated waves of smooth-muscle contraction that move material through the digestive tract.
606. kártya
Kérdés
What is an intestinal villus?
Válasz
A finger-like projection increasing the absorptive surface of the small intestine.
607. kártya
Kérdés
Which term describes breakdown of food into absorbable molecules?
Válasz
digestion
608. kártya
Kérdés
Which term describes movement of digested nutrients into transport fluids?
Válasz
absorption
609. kártya
Kérdés
Which term describes wave-like gut contractions moving contents?
Válasz
peristalsis
610. kártya
Kérdés
Which term describes a finger-like intestinal absorption projection?
Válasz
an intestinal villus
611. kártya
Kérdés
What is excretion?
Válasz
Removal of metabolic waste products from the body.
612. kártya
Kérdés
What is a nephron?
Válasz
The microscopic functional unit of the kidney that filters blood and modifies filtrate into urine.
613. kártya
Kérdés
What is ultrafiltration?
Válasz
Pressure-driven filtration of small molecules from blood into a kidney capsule while cells and most proteins remain in blood.
614. kártya
Kérdés
What is selective reabsorption?
Válasz
Recovery of useful substances and regulated amounts of water and ions from kidney filtrate into blood.
615. kártya
Kérdés
Which term describes removal of metabolic wastes?
Válasz
excretion
616. kártya
Kérdés
Which term describes the kidney's microscopic functional unit?
Válasz
a nephron
617. kártya
Kérdés
Which term describes pressure filtration at the start of a nephron?
Válasz
ultrafiltration
618. kártya
Kérdés
Which term describes return of useful substances from kidney filtrate to blood?
Válasz
selective reabsorption
619. kártya
Kérdés
What is skeletal muscle?
Válasz
Striated voluntary muscle attached to the skeleton and used for movement and posture.
620. kártya
Kérdés
What is an antagonistic muscle pair?
Válasz
Two muscles producing opposite movements at a joint because muscles pull but do not push.
621. kártya
Kérdés
How do nervous and endocrine signaling generally differ?
Válasz
Neural signals are rapid and targeted; hormonal signals are usually slower, longer-lasting, and distributed through body fluids.
622. kártya
Kérdés
Why does a circulating hormone affect only some cells?
Válasz
Only target cells express receptors that recognize the hormone and activate a response.
623. kártya
Kérdés
Which term describes voluntary striated muscle that moves the skeleton?
Válasz
skeletal muscle
624. kártya
Kérdés
Which term describes two muscles producing opposite joint movements?
Válasz
an antagonistic muscle pair
625. kártya
Kérdés
What is the final absorbable product of most dietary carbohydrate digestion?
Válasz
Monosaccharides, especially glucose.
626. kártya
Kérdés
What are the main absorbable products of protein digestion?
Válasz
Amino acids and small peptides that are completed to amino acids during absorption.
627. kártya
Kérdés
How is the small intestine adapted for absorption?
Válasz
Folds, villi, and microvilli increase area; a thin epithelium, rich blood supply, and lymph vessels support transport.
628. kártya
Kérdés
Name three integrative roles of the liver.
Válasz
It processes absorbed nutrients, regulates blood chemistry, detoxifies substances, produces bile, and converts ammonia to urea; any three are sufficient.
629. kártya
Kérdés
Why are blood cells and most plasma proteins absent from normal kidney filtrate?
Válasz
They are too large to cross the filtration barrier.
630. kártya
Kérdés
How do muscles move a bone at a joint?
Válasz
Contraction shortens the muscle, pulling through a tendon on the bone.
631. kártya
Kérdés
Why are antagonistic muscles needed at many joints?
Válasz
A muscle can pull in one direction but cannot push itself back, so an opposing muscle produces the reverse movement.
632. kártya
Kérdés
Why must organ systems be integrated rather than acting independently?
Válasz
Each system depends on materials, signals, waste removal, and stable conditions supplied by other systems.
633. kártya
Kérdés
Why do many absorbed lipids enter lymph before blood?
Válasz
Intestinal cells package them into lipoprotein particles too large to enter ordinary blood capillaries directly.
634. kártya
Kérdés
Why is glucose normally absent from final urine?
Válasz
Filtered glucose is selectively reabsorbed into blood when transporter capacity is not exceeded.
635. kártya
Kérdés
How do respiratory, circulatory, and muscular systems cooperate during exercise?
Válasz
Ventilation supplies oxygen, circulation transports gases and fuels, and muscles use ATP while returning carbon dioxide, heat, and metabolites.
636. kártya
Kérdés
How do liver, circulation, and kidneys cooperate in nitrogen-waste removal?
Válasz
The liver converts toxic ammonia to urea, blood carries urea, and kidneys filter and excrete it.
637. kártya
Kérdés
What is a pathogen?
Válasz
A biological agent capable of causing disease.
638. kártya
Kérdés
What is an antigen?
Válasz
A molecule recognized specifically by an antibody or lymphocyte receptor.
639. kártya
Kérdés
What is innate immunity?
Válasz
Rapid, nonspecific defense mechanisms present without prior exposure.
640. kártya
Kérdés
What is adaptive immunity?
Válasz
Specific defense that develops through lymphocyte activation and can form memory.
641. kártya
Kérdés
Which term describes a disease-causing biological agent?
Válasz
a pathogen
642. kártya
Kérdés
Which term describes a molecule specifically recognized by adaptive immune receptors?
Válasz
an antigen
643. kártya
Kérdés
Which term describes rapid nonspecific immune defense?
Válasz
innate immunity
644. kártya
Kérdés
Which term describes specific immune defense capable of memory?
Válasz
adaptive immunity
645. kártya
Kérdés
What is a phagocyte?
Válasz
A cell that engulfs and digests microbes, particles, or damaged cells.
646. kártya
Kérdés
What is a lymphocyte?
Válasz
An adaptive immune cell with receptors specific to particular antigens.
647. kártya
Kérdés
What is an antibody?
Válasz
A secreted immunoglobulin that binds a specific antigen.
648. kártya
Kérdés
What is a B lymphocyte?
Válasz
A lymphocyte that can differentiate into antibody-secreting plasma cells and memory cells.
649. kártya
Kérdés
Which term describes an engulfing immune cell?
Válasz
a phagocyte
650. kártya
Kérdés
Which term describes an antigen-specific adaptive immune cell?
Válasz
a lymphocyte
651. kártya
Kérdés
Which term describes a secreted antigen-binding immunoglobulin?
Válasz
an antibody
652. kártya
Kérdés
Which term describes the lymphocyte lineage that produces antibody-secreting cells?
Válasz
a B lymphocyte
653. kártya
Kérdés
What is a helper T cell?
Válasz
A lymphocyte that coordinates immune responses through contact signals and cytokines.
654. kártya
Kérdés
What is an immune memory cell?
Válasz
A long-lived lymphocyte that responds rapidly after re-exposure to its antigen.
655. kártya
Kérdés
What is vaccination?
Válasz
Deliberate exposure to a safe form or component of an antigen to generate protective immune memory.
656. kártya
Kérdés
What is an antibiotic?
Válasz
A substance that kills bacteria or inhibits their growth at clinically useful doses.
657. kártya
Kérdés
Which term describes the T cell that coordinates other immune cells?
Válasz
a helper T cell
658. kártya
Kérdés
Which term describes a long-lived lymphocyte enabling faster re-exposure response?
Válasz
an immune memory cell
659. kártya
Kérdés
Which term describes safe antigen exposure used to create immune memory?
Válasz
vaccination
660. kártya
Kérdés
Which term describes a drug acting against bacteria?
Válasz
an antibiotic
661. kártya
Kérdés
What are examples of first-line defenses against pathogens?
Válasz
Intact skin, mucus, cilia, antimicrobial secretions, stomach acidity, and competing microbiota.
662. kártya
Kérdés
How does inflammation help defend damaged tissue?
Válasz
It increases local blood flow and vessel permeability and recruits immune cells and defensive molecules.
663. kártya
Kérdés
What happens during phagocytosis?
Válasz
A cell surrounds a particle in a vesicle, then fuses it with digestive compartments to destroy or process it.
664. kártya
Kérdés
How can antibodies help eliminate a pathogen?
Válasz
They can neutralize targets, block attachment, clump particles, and mark them for phagocytosis or complement attack.
665. kártya
Kérdés
Why can a vaccine generate protection without causing the full disease?
Válasz
It presents antigen in a weakened, inactivated, partial, or encoded form that stimulates immunity with much lower risk.
666. kártya
Kérdés
Why do antibiotics not treat viral infections?
Válasz
Viruses lack the bacterial structures and independent metabolic processes targeted by antibiotics.
667. kártya
Kérdés
What determines the antigen specificity of a lymphocyte?
Válasz
The molecular shape and chemistry of its unique surface receptor.
668. kártya
Kérdés
What is clonal selection?
Válasz
An antigen activates lymphocytes with matching receptors, causing them to proliferate and differentiate.
669. kártya
Kérdés
Why is a secondary adaptive immune response usually faster and stronger?
Válasz
Memory cells are more numerous and activate rapidly, producing effective cells and antibodies sooner.
670. kártya
Kérdés
How can high vaccination coverage protect some unvaccinated people?
Válasz
Reduced transmission makes encounters with infectious individuals less likely, though protection is incomplete and pathogen-dependent.
671. kártya
Kérdés
How does antibiotic use select for resistant bacteria?
Válasz
Susceptible bacteria are removed while resistant variants survive and reproduce, increasing resistance-allele frequency.
672. kártya
Kérdés
Why can unnecessary or incomplete antibiotic exposure promote resistance?
Válasz
It creates selection favoring resistant cells while potentially leaving surviving bacteria to multiply and spread.
673. kártya
Kérdés
What is an allergy?
Válasz
An immune response to a normally harmless antigen that causes tissue symptoms or damage.
674. kártya
Kérdés
What is asexual reproduction?
Válasz
Production of offspring from one parent without fusion of gametes.
675. kártya
Kérdés
What is sexual reproduction?
Válasz
Production of offspring involving fusion of haploid gametes.
676. kártya
Kérdés
What is a gamete?
Válasz
A haploid reproductive cell able to fuse with another gamete.
677. kártya
Kérdés
What is fertilization?
Válasz
Fusion of gamete nuclei to form a diploid zygote.
678. kártya
Kérdés
Which term describes reproduction without gamete fusion?
Válasz
asexual reproduction
679. kártya
Kérdés
Which term describes reproduction involving gamete fusion?
Válasz
sexual reproduction
680. kártya
Kérdés
Which term describes a haploid reproductive cell?
Válasz
a gamete
681. kártya
Kérdés
Which term describes fusion of gamete nuclei?
Válasz
fertilization
682. kártya
Kérdés
What is a zygote?
Válasz
The diploid cell formed by fertilization.
683. kártya
Kérdés
What is meiosis?
Válasz
Cell division that halves chromosome number and usually produces genetically varied haploid cells.
684. kártya
Kérdés
What is ovulation?
Válasz
Release of a secondary oocyte from an ovary.
685. kártya
Kérdés
What is implantation?
Válasz
Attachment and embedding of an early embryo in the uterine lining.
686. kártya
Kérdés
Which term describes the first diploid cell after fertilization?
Válasz
a zygote
687. kártya
Kérdés
Which term describes division producing varied haploid cells?
Válasz
meiosis
688. kártya
Kérdés
Which term describes release of an oocyte from an ovary?
Válasz
ovulation
689. kártya
Kérdés
Which term describes embedding of an early embryo in the uterine lining?
Válasz
implantation
690. kártya
Kérdés
What is the placenta?
Válasz
A temporary organ that exchanges materials between maternal and fetal blood supplies without normally mixing them directly.
691. kártya
Kérdés
What is pollination?
Válasz
Transfer of pollen from an anther to a receptive stigma.
692. kártya
Kérdés
Why does sexual reproduction usually produce more genetic variation than asexual reproduction?
Válasz
Meiosis reshuffles alleles and random fertilization combines genomes from two gametes.
693. kártya
Kérdés
Why must gametes be haploid?
Válasz
Fusion of two haploid gametes restores the diploid chromosome number instead of doubling it each generation.
694. kártya
Kérdés
Which term describes the maternal-fetal exchange organ?
Válasz
the placenta
695. kártya
Kérdés
Which term describes transfer of pollen to a stigma?
Válasz
pollination
696. kártya
Kérdés
What are major roles of FSH in the ovarian cycle?
Válasz
It stimulates follicle development and supports estrogen secretion.
697. kártya
Kérdés
What is a major role of the mid-cycle LH surge?
Válasz
It triggers ovulation and formation of the corpus luteum.
698. kártya
Kérdés
How does estrogen contribute to the uterine cycle?
Válasz
It promotes repair and thickening of the uterine lining after menstruation.
699. kártya
Kérdés
How does progesterone contribute to the uterine cycle?
Válasz
It maintains a thick, secretory uterine lining after ovulation.
700. kártya
Kérdés
Where does human fertilization usually occur?
Válasz
In an oviduct, before the early embryo reaches the uterus.
701. kártya
Kérdés
What happens after compatible pollen reaches a flower's stigma?
Válasz
A pollen tube grows toward an ovule and delivers male nuclei for fertilization.
702. kártya
Kérdés
Why does menstruation usually begin if pregnancy does not occur?
Válasz
The corpus luteum degenerates, progesterone and estrogen fall, and the uterine lining is no longer maintained.
703. kártya
Kérdés
What substances commonly cross the placenta between mother and fetus?
Válasz
Oxygen and nutrients move toward the fetus; carbon dioxide and nitrogenous wastes move toward the mother.
704. kártya
Kérdés
How can contraception prevent pregnancy in different ways?
Válasz
Methods can inhibit ovulation, block sperm from reaching an egg, prevent fertilization, or permanently interrupt the reproductive ducts.
705. kártya
Kérdés
What is homeostasis?
Válasz
Maintenance of internal conditions within ranges compatible with normal function despite change.
706. kártya
Kérdés
What is negative feedback?
Válasz
Control in which a deviation triggers responses that oppose the original change.
707. kártya
Kérdés
What is a set point?
Válasz
The target value or range around which a regulated variable is maintained.
708. kártya
Kérdés
What is a homeostatic receptor?
Válasz
A sensor that detects a change in a regulated variable.
709. kártya
Kérdés
Which term describes maintenance of a stable functional internal environment?
Válasz
homeostasis
710. kártya
Kérdés
Which term describes feedback that counteracts a deviation?
Válasz
negative feedback
711. kártya
Kérdés
Which term describes the target around which a variable is regulated?
Válasz
a set point
712. kártya
Kérdés
Which term describes the sensor in a feedback system?
Válasz
a homeostatic receptor
713. kártya
Kérdés
What is a control center?
Válasz
The component that compares information with a target and coordinates a response.
714. kártya
Kérdés
What is an effector?
Válasz
A muscle, gland, or other component that carries out a control response.
715. kártya
Kérdés
What is thermoregulation?
Válasz
Control of body temperature within a functional range.
716. kártya
Kérdés
What is vasodilation?
Válasz
Widening of blood vessels, often increasing blood flow near the skin.
717. kártya
Kérdés
Which term describes the feedback component that evaluates input and directs a response?
Válasz
a control center
718. kártya
Kérdés
Which term describes the component that executes a physiological response?
Válasz
an effector
719. kártya
Kérdés
Which term describes physiological regulation of body temperature?
Válasz
thermoregulation
720. kártya
Kérdés
Which term describes widening of blood vessels?
Válasz
vasodilation
721. kártya
Kérdés
What is vasoconstriction?
Válasz
Narrowing of blood vessels, often reducing blood flow near the skin.
722. kártya
Kérdés
What is insulin?
Válasz
A pancreatic hormone that lowers elevated blood glucose by promoting uptake and storage.
723. kártya
Kérdés
What is glucagon?
Válasz
A pancreatic hormone that raises low blood glucose by promoting release of stored fuel.
724. kártya
Kérdés
What are the main components of a homeostatic feedback loop?
Válasz
A regulated variable, receptor, control center, effectors, and responses that alter the variable.
725. kártya
Kérdés
Which term describes narrowing of blood vessels?
Válasz
vasoconstriction
726. kártya
Kérdés
Which term describes the pancreatic hormone that lowers blood glucose?
Válasz
insulin
727. kártya
Kérdés
Which term describes the pancreatic hormone that raises blood glucose?
Válasz
glucagon
728. kártya
Kérdés
What happens when blood glucose rises after a meal?
Válasz
Insulin secretion increases, promoting glucose uptake and storage so blood glucose falls toward its normal range.
729. kártya
Kérdés
What happens when blood glucose falls during fasting?
Válasz
Glucagon secretion increases, promoting glycogen breakdown and glucose release by the liver.
730. kártya
Kérdés
How does sweating cool the body?
Válasz
Evaporation of water from skin transfers heat to the environment.
731. kártya
Kérdés
How does skin vasodilation increase heat loss?
Válasz
It brings more warm blood near the surface, increasing transfer of heat to the environment.
732. kártya
Kérdés
How does shivering warm the body?
Válasz
Rapid involuntary muscle contractions increase respiration and heat production.
733. kártya
Kérdés
Does homeostasis keep internal conditions perfectly constant?
Válasz
No. Variables fluctuate within controlled ranges around target values.
734. kártya
Kérdés
How does ADH help conserve water?
Válasz
It increases water permeability in kidney collecting ducts, so more water is reabsorbed and urine becomes more concentrated.
735. kártya
Kérdés
How should ADH secretion change during dehydration?
Válasz
It should increase, promoting greater water reabsorption by the kidneys.
736. kártya
Kérdés
How does positive feedback differ from negative feedback?
Válasz
Positive feedback amplifies a change until an endpoint; negative feedback opposes a change and stabilizes a variable.
737. kártya
Kérdés
Why can diabetes mellitus cause persistently high blood glucose?
Válasz
Insulin production may be insufficient or target cells may respond poorly to insulin.
738. kártya
Kérdés
What is biological evolution?
Válasz
Change in heritable characteristics or allele frequencies of a population across generations.
739. kártya
Kérdés
What is allele frequency?
Válasz
The proportion of gene copies in a population represented by a particular allele.
740. kártya
Kérdés
What is microevolution?
Válasz
Evolutionary change in allele frequencies within populations over relatively short timescales.
741. kártya
Kérdés
What is speciation?
Válasz
Evolutionary formation of new species.
742. kártya
Kérdés
Which term describes change in a population's heritable composition across generations?
Válasz
biological evolution
743. kártya
Kérdés
Which term describes the proportion of a population's gene copies that are one allele?
Válasz
allele frequency
744. kártya
Kérdés
Which term describes short-timescale allele-frequency change within populations?
Válasz
microevolution
745. kártya
Kérdés
Which term describes formation of new species?
Válasz
speciation
746. kártya
Kérdés
What is reproductive isolation?
Válasz
Barriers that prevent or greatly reduce gene flow between populations.
747. kártya
Kérdés
What is allopatric speciation?
Válasz
Speciation after populations become geographically separated and diverge.
748. kártya
Kérdés
What is sympatric speciation?
Válasz
Speciation without geographic separation, through reproductive isolation within the same area.
749. kártya
Kérdés
What are homologous structures?
Válasz
Structures similar because they were inherited from a common ancestor, even if their functions differ.
750. kártya
Kérdés
Which term describes barriers reducing gene flow between populations?
Válasz
reproductive isolation
751. kártya
Kérdés
Which term describes speciation following geographic separation?
Válasz
allopatric speciation
752. kártya
Kérdés
Which term describes speciation within the same geographic area?
Válasz
sympatric speciation
753. kártya
Kérdés
Which term describes structures similar through common ancestry?
Válasz
homologous structures
754. kártya
Kérdés
What are analogous structures?
Válasz
Structures with similar functions that evolved independently rather than from the same ancestral structure.
755. kártya
Kérdés
What is a common ancestor?
Válasz
An ancestral population from which two or more descendant lineages evolved.
756. kártya
Kérdés
How does the fossil record provide evidence for evolution?
Válasz
It documents organisms from different times, including appearance, change, persistence, and extinction of lineages.
757. kártya
Kérdés
How do DNA and protein sequences provide evidence of common ancestry?
Válasz
Shared sequences are inherited; greater similarity generally indicates more recent common ancestry.
758. kártya
Kérdés
Which term describes functionally similar structures of independent evolutionary origin?
Válasz
analogous structures
759. kártya
Kérdés
Which term describes an ancestral population shared by descendant lineages?
Válasz
a common ancestor
760. kártya
Kérdés
What is the evolutionary significance of extinction?
Válasz
It permanently ends a lineage and can alter ecological opportunities and the future diversification of survivors.
761. kártya
Kérdés
Do individual organisms evolve during their lifetimes?
Válasz
No. Individuals develop and acclimate; evolution is heritable change in populations across generations.
762. kártya
Kérdés
Why is evolution represented as a branching tree rather than a ladder?
Válasz
Lineages split from common ancestors; living species are not arranged as stages toward a single goal.
763. kártya
Kérdés
How can island species support evolutionary explanations?
Válasz
Their similarities to nearby mainland ancestors and unique local adaptations fit divergence after colonization and isolation.
764. kártya
Kérdés
How can geographic isolation lead to reproductive isolation?
Válasz
Separated populations accumulate different mutations and experience different selection and drift until interbreeding is reduced.
765. kártya
Kérdés
Why can continuing gene flow slow speciation?
Válasz
Movement of alleles between populations counteracts genetic divergence.
766. kártya
Kérdés
Why can unrelated species evolve similar traits?
Válasz
Similar environmental challenges can favor similar functional solutions through convergent evolution.
767. kártya
Kérdés
Which parts of evolution are random and which are nonrandom?
Válasz
Mutation and many sampling effects are random with respect to need; natural selection nonrandomly favors variants that reproduce better in a given environment.
768. kártya
Kérdés
What is conservation biology?
Válasz
The science and practice of protecting biodiversity, ecological processes, and evolutionary potential.
769. kártya
Kérdés
What is habitat fragmentation?
Válasz
Division of continuous habitat into smaller, isolated patches.
770. kártya
Kérdés
What is an endangered species?
Válasz
A species facing a high risk of extinction in the wild.
771. kártya
Kérdés
What is in situ conservation?
Válasz
Protection of species in their natural habitats and ecological communities.
772. kártya
Kérdés
Which term describes the protection of biodiversity and ecological processes?
Válasz
conservation biology
773. kártya
Kérdés
Which term describes division of habitat into isolated patches?
Válasz
habitat fragmentation
774. kártya
Kérdés
Which term describes a species at high risk of extinction?
Válasz
an endangered species
775. kártya
Kérdés
Which term describes conservation within natural habitat?
Válasz
in situ conservation
776. kártya
Kérdés
What is ex situ conservation?
Válasz
Protection of organisms or genetic material outside the natural habitat.
777. kártya
Kérdés
What is a population bottleneck?
Válasz
A sharp population reduction that can remove genetic variation by chance.
778. kártya
Kérdés
What is a wildlife corridor?
Válasz
Habitat connecting isolated patches to permit movement and gene flow.
779. kártya
Kérdés
What major human-driven processes threaten biodiversity?
Válasz
Habitat loss, overexploitation, invasive species, pollution, and climate change.
780. kártya
Kérdés
Which term describes conservation outside natural habitat?
Válasz
ex situ conservation
781. kártya
Kérdés
Which term describes a severe population reduction that loses genetic diversity?
Válasz
a population bottleneck
782. kártya
Kérdés
Which term describes habitat linking isolated populations?
Válasz
a wildlife corridor
783. kártya
Kérdés
What makes a protected area more effective than a boundary alone?
Válasz
Adequate size, representative habitat, enforcement, connectivity, local support, and management of external threats.
784. kártya
Kérdés
Why is long-term population monitoring important in conservation?
Válasz
It reveals trends, tests whether management works, and provides early warning of decline.
785. kártya
Kérdés
How can ecosystem services support the case for conservation?
Válasz
Healthy ecosystems provide benefits such as pollination, water purification, carbon storage, soil formation, and cultural value.
786. kártya
Kérdés
Why are very small populations especially vulnerable to extinction?
Válasz
Chance events, inbreeding, low genetic diversity, and difficulty finding mates can reinforce decline.
787. kártya
Kérdés
What are benefits and limits of captive-breeding programs?
Válasz
They can prevent immediate extinction and manage breeding, but may lose diversity, alter behavior, and fail without safe habitat for release.
788. kártya
Kérdés
Why can controlling an invasive species aid conservation?
Válasz
It can reduce predation, competition, disease, or habitat alteration affecting native species.
789. kártya
Kérdés
Why must conservation priorities consider more than species count?
Válasz
Endemism, evolutionary distinctness, ecological roles, threat severity, feasibility, and human needs also matter.
790. kártya
Kérdés
What is an adaptation?
Válasz
A heritable characteristic that increases reproductive success in a particular environment.
791. kártya
Kérdés
What is acclimation?
Válasz
A reversible physiological or behavioral adjustment by an individual to environmental change.
792. kártya
Kérdés
What is a structural adaptation?
Válasz
An inherited anatomical feature that improves performance in an environment.
793. kártya
Kérdés
What is a physiological adaptation?
Válasz
An inherited functional or biochemical feature that improves performance in an environment.
794. kártya
Kérdés
Which term describes a heritable trait improving reproductive success in context?
Válasz
an adaptation
795. kártya
Kérdés
Which term describes an individual's reversible adjustment to environmental change?
Válasz
acclimation
796. kártya
Kérdés
Which term describes an adaptive anatomical feature?
Válasz
a structural adaptation
797. kártya
Kérdés
Which term describes an adaptive functional or biochemical feature?
Válasz
a physiological adaptation
798. kártya
Kérdés
What is a behavioral adaptation?
Válasz
An inherited behavior pattern that improves survival or reproduction.
799. kártya
Kérdés
What is an environmental tolerance range?
Válasz
The range of an abiotic condition within which an organism can survive and reproduce.
800. kártya
Kérdés
What is evolutionary fitness?
Válasz
Relative contribution of an individual or genotype to future generations.
801. kártya
Kérdés
How can a thick cuticle and reduced leaves help a desert plant?
Válasz
The cuticle lowers surface permeability, while smaller leaves reduce the area from which water can evaporate.
802. kártya
Kérdés
Which term describes an adaptive behavior pattern?
Válasz
a behavioral adaptation
803. kártya
Kérdés
Which term describes the survivable range of an abiotic condition?
Válasz
an environmental tolerance range
804. kártya
Kérdés
Which term describes relative reproductive contribution to future generations?
Válasz
evolutionary fitness
805. kártya
Kérdés
How can a streamlined body adapt an aquatic animal to movement?
Válasz
It reduces drag, lowering the energy needed to move through water.
806. kártya
Kérdés
Does an organism develop an adaptation because it needs one?
Válasz
No. Heritable variants arise without regard to need, and selection changes their frequencies across generations.
807. kártya
Kérdés
Why may organisms from different thermal environments have enzymes with different temperature optima?
Válasz
Selection favors protein structures that balance flexibility and stability under local temperatures.
808. kártya
Kérdés
Why is an adaptation rarely beneficial in every environment?
Válasz
Traits carry costs and their advantage depends on local resources, competitors, predators, and physical conditions.
809. kártya
Kérdés
How does phenotypic plasticity differ from genetic adaptation?
Válasz
Plasticity lets one genotype produce different phenotypes; adaptation is a heritable population trait shaped across generations.
810. kártya
Kérdés
What is local adaptation?
Válasz
A population has higher fitness in its home environment than foreign populations because selection favored local traits.
811. kártya
Kérdés
What is an ecological niche?
Válasz
The set of environmental conditions, resources, interactions, and functional roles associated with a species.
812. kártya
Kérdés
What is a habitat?
Válasz
The physical place or environment where an organism lives.
813. kártya
Kérdés
What is a fundamental niche?
Válasz
The full range of conditions and resources a species could use without limiting biotic interactions.
814. kártya
Kérdés
What is a realized niche?
Válasz
The conditions and resources a species actually uses after competition and other interactions.
815. kártya
Kérdés
Which term describes a species' environmental requirements and ecological role?
Válasz
an ecological niche
816. kártya
Kérdés
Which term describes the place where an organism lives?
Válasz
a habitat
817. kártya
Kérdés
Which term describes the potential niche without limiting biotic interactions?
Válasz
a fundamental niche
818. kártya
Kérdés
Which term describes the niche actually occupied in nature?
Válasz
a realized niche
819. kártya
Kérdés
What is competition?
Válasz
An interaction in which organisms reduce one another's access to a limited resource.
820. kártya
Kérdés
What is mutualism?
Válasz
An interaction in which both participating species benefit.
821. kártya
Kérdés
What is predation?
Válasz
An interaction in which one organism kills and consumes another.
822. kártya
Kérdés
How does a habitat differ from a niche?
Válasz
A habitat is where an organism lives; a niche includes how it uses conditions and resources and interacts there.
823. kártya
Kérdés
Which term describes an interaction over a limited resource that harms both competitors?
Válasz
competition
824. kártya
Kérdés
Which term describes an interspecific interaction benefiting both partners?
Válasz
mutualism
825. kártya
Kérdés
Which term describes an interaction where one organism kills and eats another?
Válasz
predation
826. kártya
Kérdés
What kinds of factors define a niche?
Válasz
Abiotic factors such as temperature and moisture, plus biotic factors such as food, competitors, predators, and partners.
827. kártya
Kérdés
What does competitive exclusion predict?
Válasz
Species with effectively identical niches cannot coexist indefinitely under stable conditions; one is excluded or niches diverge.
828. kártya
Kérdés
How can resource partitioning reduce competition?
Válasz
Species use different resources, places, or times, reducing niche overlap.
829. kártya
Kérdés
What is a keystone species?
Válasz
A species whose effect on community structure is disproportionately large relative to its abundance.
830. kártya
Kérdés
Why can an introduced species expand rapidly in a new community?
Válasz
It may encounter abundant resources, suitable climate, and fewer predators, pathogens, or competitors.
831. kártya
Kérdés
Can an organism alter the niche conditions of other species?
Válasz
Yes. Ecosystem engineers modify habitat structure or resource availability, changing opportunities for other organisms.
832. kártya
Kérdés
What is a population?
Válasz
Individuals of the same species living in the same area at the same time.
833. kártya
Kérdés
What is an ecological community?
Válasz
Populations of different species living and interacting in an area.
834. kártya
Kérdés
What is an ecosystem?
Válasz
A community together with its physical environment and their interactions.
835. kártya
Kérdés
What is carrying capacity?
Válasz
The population size an environment can sustain over time under given conditions.
836. kártya
Kérdés
Which term describes same-species individuals sharing an area and time?
Válasz
a population
837. kártya
Kérdés
Which term describes interacting populations of different species?
Válasz
an ecological community
838. kártya
Kérdés
Which term describes a community plus its abiotic environment?
Válasz
an ecosystem
839. kártya
Kérdés
Which term describes the long-term supportable population size?
Válasz
carrying capacity
840. kártya
Kérdés
What is population density?
Válasz
The number of individuals per unit area or volume.
841. kártya
Kérdés
What is a limiting factor?
Válasz
A resource or condition that restricts population growth or distribution.
842. kártya
Kérdés
What is a density-dependent factor?
Válasz
A factor whose effect strengthens as population density increases.
843. kártya
Kérdés
What is a density-independent factor?
Válasz
A factor whose effect is not primarily determined by population density.
844. kártya
Kérdés
Which term describes individuals per unit area or volume?
Válasz
population density
845. kártya
Kérdés
Which term describes a resource or condition restricting a population?
Válasz
a limiting factor
846. kártya
Kérdés
Which term describes a factor with stronger effects at higher density?
Válasz
a density-dependent factor
847. kártya
Kérdés
Which term describes a factor acting largely regardless of population density?
Válasz
a density-independent factor
848. kártya
Kérdés
What is exponential population growth?
Válasz
Growth at a constant per-capita rate, producing a J-shaped curve under ideal conditions.
849. kártya
Kérdés
What is logistic population growth?
Válasz
Growth that slows as population size approaches carrying capacity, producing an S-shaped model.
850. kártya
Kérdés
What four processes directly change population size?
Válasz
Births and immigration increase it; deaths and emigration decrease it.
851. kártya
Kérdés
Under what conditions can exponential growth occur temporarily?
Válasz
Resources are abundant and limiting effects such as competition, disease, and predation are weak.
852. kártya
Kérdés
Which term describes J-shaped growth at constant per-capita rate?
Válasz
exponential population growth
853. kártya
Kérdés
Which term describes S-shaped growth that slows near carrying capacity?
Válasz
logistic population growth
854. kártya
Kérdés
Why is infectious disease often density dependent?
Válasz
Close or frequent contact at high density increases transmission opportunities.
855. kártya
Kérdés
Give an example of a density-independent population factor.
Válasz
A severe storm, wildfire, drought, or freeze can affect populations regardless of their initial density.
856. kártya
Kérdés
When is quadrat sampling useful?
Válasz
For estimating abundance or frequency of sessile or slow-moving organisms in defined areas.
857. kártya
Kérdés
What can a transect reveal?
Válasz
How species occurrence or abundance changes along an environmental gradient.
858. kártya
Kérdés
What can happen when a population overshoots carrying capacity?
Válasz
Resource depletion may raise mortality or lower reproduction, causing decline or oscillation.
859. kártya
Kérdés
What is the basic mark–recapture estimate of population size?
Válasz
First sample marked × second sample total ÷ marked individuals recaptured.
860. kártya
Kérdés
What assumptions improve a mark–recapture estimate?
Válasz
Marks persist and do not affect survival, marked individuals mix, capture probability is similar, and the population is effectively closed.
861. kártya
Kérdés
Why does a correlation between two population variables not prove causation?
Válasz
A third factor, reverse influence, chance, or biased sampling could produce the association.
862. kártya
Kérdés
What is a trophic level?
Válasz
A feeding position in a food chain or web.
863. kártya
Kérdés
What is a producer?
Válasz
An autotroph that converts inorganic carbon into organic matter.
864. kártya
Kérdés
What is a consumer?
Válasz
An organism obtaining energy and matter by eating other organisms or organic material.
865. kártya
Kérdés
What is a decomposer?
Válasz
An organism that externally digests dead material and wastes and absorbs the products.
866. kártya
Kérdés
Which term describes a feeding position in an ecosystem?
Válasz
a trophic level
867. kártya
Kérdés
Which term describes an autotroph forming organic matter?
Válasz
a producer
868. kártya
Kérdés
Which term describes an organism feeding on other organic matter?
Válasz
a consumer
869. kártya
Kérdés
Which term describes an organism digesting dead organic matter externally?
Válasz
a decomposer
870. kártya
Kérdés
What is a food chain?
Válasz
A linear representation of feeding and energy-transfer relationships.
871. kártya
Kérdés
What is a food web?
Válasz
A network of interconnected feeding relationships in a community.
872. kártya
Kérdés
What is gross primary productivity?
Válasz
The total rate at which producers capture energy into organic matter.
873. kártya
Kérdés
What is net primary productivity?
Válasz
Producer energy stored as new biomass after subtracting producer respiration from gross primary productivity.
874. kártya
Kérdés
Which term describes a linear feeding sequence?
Válasz
a food chain
875. kártya
Kérdés
Which term describes a network of connected food chains?
Válasz
a food web
876. kártya
Kérdés
Which term describes the total producer energy-capture rate?
Válasz
gross primary productivity
877. kártya
Kérdés
Which term describes producer biomass gain after respiration?
Válasz
net primary productivity
878. kártya
Kérdés
What is ecological productivity?
Válasz
The rate of biomass or energy production per unit area or volume.
879. kártya
Kérdés
What is a biogeochemical cycle?
Válasz
Movement of an element or compound through organisms and the physical environment.
880. kártya
Kérdés
Why is less energy available at each higher trophic level?
Válasz
Not all biomass is eaten or digested, and organisms use energy in respiration, movement, maintenance, and heat loss.
881. kártya
Kérdés
Why does energy flow rather than cycle through an ecosystem?
Válasz
Energy enters mainly as light and ultimately disperses as heat, which ecosystems cannot fully recycle.
882. kártya
Kérdés
Which term describes the rate of biomass or energy production?
Válasz
ecological productivity
883. kártya
Kérdés
Which term describes cycling of matter through living and nonliving reservoirs?
Válasz
a biogeochemical cycle
884. kártya
Kérdés
Why can matter cycle through an ecosystem?
Válasz
Atoms are conserved and repeatedly transferred among organisms, detritus, soil, water, and atmosphere.
885. kártya
Kérdés
Why is a pyramid of energy always upright?
Válasz
Usable energy decreases between trophic levels because every transfer includes losses.
886. kártya
Kérdés
How are gross and net primary productivity related?
Válasz
NPP = GPP − producer respiration.
887. kártya
Kérdés
How do decomposers support nutrient cycling?
Válasz
They break down dead material and wastes, releasing inorganic nutrients for reuse.
888. kártya
Kérdés
What processes move carbon rapidly between organisms and the atmosphere?
Válasz
Photosynthesis removes carbon dioxide; respiration, decomposition, and combustion release it.
889. kártya
Kérdés
Why is nitrogen fixation important?
Válasz
It converts atmospheric nitrogen gas into forms that can enter biological nitrogen metabolism.
890. kártya
Kérdés
How can excess nitrogen or phosphorus cause eutrophication?
Válasz
Nutrient enrichment drives algal growth; decomposition of the biomass consumes oxygen and can create hypoxic water.
891. kártya
Kérdés
Why can a persistent pollutant reach higher concentrations at higher trophic levels?
Válasz
Predators consume contaminant stored in many prey, and the substance is not readily broken down or excreted.
892. kártya
Kérdés
How is trophic-transfer efficiency calculated?
Válasz
Energy or biomass gained by the higher trophic level ÷ energy or biomass available at the lower level × 100%.
893. kártya
Kérdés
What is phenotypic variation?
Válasz
Differences in observable traits among individuals of a population.
894. kártya
Kérdés
What is heritable variation?
Válasz
Trait differences that can be transmitted genetically to offspring.
895. kártya
Kérdés
What is a selection pressure?
Válasz
An environmental factor causing differences in survival or reproduction among phenotypes.
896. kártya
Kérdés
What is relative fitness?
Válasz
An individual's reproductive success compared with others in the population.
897. kártya
Kérdés
Which term describes observable differences among individuals?
Válasz
phenotypic variation
898. kártya
Kérdés
Which term describes genetically transmissible trait differences?
Válasz
heritable variation
899. kártya
Kérdés
Which term describes an environmental factor producing differential reproductive success?
Válasz
a selection pressure
900. kártya
Kérdés
Which term describes reproductive success relative to other individuals?
Válasz
relative fitness
901. kártya
Kérdés
What is directional selection?
Válasz
Selection favoring one extreme phenotype and shifting a population's trait distribution.
902. kártya
Kérdés
What is stabilizing selection?
Válasz
Selection favoring intermediate phenotypes and acting against extremes.
903. kártya
Kérdés
What is disruptive selection?
Válasz
Selection favoring both extreme phenotypes over intermediates.
904. kártya
Kérdés
What is sexual selection?
Válasz
Selection arising from differences in mating success.
905. kártya
Kérdés
Which term describes selection shifting a trait toward one extreme?
Válasz
directional selection
906. kártya
Kérdés
Which term describes selection favoring intermediate phenotypes?
Válasz
stabilizing selection
907. kártya
Kérdés
Which term describes selection favoring both trait extremes?
Válasz
disruptive selection
908. kártya
Kérdés
Which term describes selection caused by unequal mating success?
Válasz
sexual selection
909. kártya
Kérdés
What conditions are required for natural selection?
Válasz
Individuals vary, some variation is heritable, more offspring are produced than can reproduce, and variants differ in reproductive success.
910. kártya
Kérdés
How does natural selection produce antibiotic-resistant bacterial populations?
Válasz
Existing resistant variants survive treatment and reproduce more than susceptible bacteria.
911. kártya
Kérdés
Does an antibiotic cause bacteria to mutate specifically toward resistance?
Válasz
No. Resistance variants arise without regard to need; treatment selects among them.
912. kártya
Kérdés
Can an individual become genetically adapted through natural selection?
Válasz
No. Selection acts on individuals, but adaptation is a population change across generations.
913. kártya
Kérdés
How does artificial selection differ from natural selection?
Válasz
Humans choose breeding traits in artificial selection; environmental conditions determine differential reproduction in natural selection.
914. kártya
Kérdés
How does natural selection change a population?
Válasz
Individuals with advantageous heritable variants leave more offspring, increasing those alleles over generations.
915. kártya
Kérdés
Why is fitness environment-dependent?
Válasz
A trait that improves reproduction in one environment may be neutral or costly in another.
916. kártya
Kérdés
How does genetic drift differ from natural selection?
Válasz
Drift changes allele frequencies by chance sampling; selection changes them through consistent fitness differences.
917. kártya
Kérdés
What is ecosystem stability?
Válasz
The capacity of an ecosystem to maintain or recover its structure and functions despite disturbance.
918. kártya
Kérdés
What is an ecological tipping point?
Válasz
A threshold beyond which feedbacks can drive a large and difficult-to-reverse ecosystem shift.
919. kártya
Kérdés
What is a mesocosm?
Válasz
A controlled, simplified ecosystem used to investigate ecological processes under more realistic conditions than a small laboratory vessel.
920. kártya
Kérdés
What is a sustainable yield?
Válasz
A harvest rate that can continue without causing long-term resource decline under prevailing conditions.
921. kártya
Kérdés
Which term describes the capacity of an ecosystem to persist or recover after disturbance?
Válasz
ecosystem stability
922. kártya
Kérdés
Which term describes a threshold triggering a major hard-to-reverse ecosystem shift?
Válasz
an ecological tipping point
923. kártya
Kérdés
Which term describes a controlled model ecosystem used for experiments?
Válasz
a mesocosm
924. kártya
Kérdés
Which term describes a harvest rate that avoids long-term depletion?
Válasz
a sustainable yield
925. kártya
Kérdés
What is eutrophication?
Válasz
Nutrient enrichment of water that stimulates excess primary production and can lead to oxygen depletion.
926. kártya
Kérdés
What is biomagnification?
Válasz
Increase in concentration of a persistent pollutant at successively higher trophic levels.
927. kártya
Kérdés
What is rewilding?
Válasz
Ecosystem restoration that rebuilds natural processes, species interactions, and self-sustaining ecological function.
928. kártya
Kérdés
What features can make an ecosystem more stable?
Válasz
Diverse functional roles, connected habitats, intact food webs, nutrient cycling, and balancing feedbacks can help the system resist or recover from disturbance.
929. kártya
Kérdés
Which term describes nutrient enrichment that can deplete oxygen in water?
Válasz
eutrophication
930. kártya
Kérdés
Which term describes increasing pollutant concentration up a food chain?
Válasz
biomagnification
931. kártya
Kérdés
Which term describes restoration focused on natural processes and self-sustaining ecosystems?
Válasz
rewilding
932. kártya
Kérdés
How could extensive Amazon deforestation push the ecosystem toward a tipping point?
Válasz
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. kártya
Kérdés
What are a benefit and a limitation of using a mesocosm?
Válasz
It allows controlled experiments with interacting organisms, but its simplified scale cannot reproduce every process or long-term influence in a natural ecosystem.
934. kártya
Kérdés
Why should a fishery harvest below an uncertain maximum sustainable yield?
Válasz
Population estimates and recruitment vary, so a safety margin reduces the chance that error or a poor breeding year drives long-term decline.
935. kártya
Kérdés
How can intensive agriculture reduce ecosystem stability?
Válasz
Habitat loss, low crop diversity, soil degradation, heavy water use, pesticides, and nutrient runoff can weaken food webs and ecosystem processes.
936. kártya
Kérdés
Why can microplastic pollution harm aquatic ecosystems?
Válasz
Small persistent particles can be ingested, carry additives or other pollutants, damage feeding and tissues, and move through food webs.
937. kártya
Kérdés
How can rewilding improve ecosystem stability?
Válasz
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. kártya
Kérdés
What is the greenhouse effect?
Válasz
Warming caused when atmospheric gases absorb and re-emit outgoing infrared radiation.
939. kártya
Kérdés
What is a greenhouse gas?
Válasz
An atmospheric gas that absorbs infrared radiation at wavelengths emitted by Earth.
940. kártya
Kérdés
What is carbon dioxide (CO₂)?
Válasz
A long-lived greenhouse gas increased mainly by fossil-fuel combustion, cement production, and land-use change.
941. kártya
Kérdés
What is methane (CH₄)?
Válasz
A potent greenhouse gas emitted by sources including fossil-fuel systems, livestock, rice cultivation, wetlands, and waste.
942. kártya
Kérdés
Which term describes warming from absorption and re-emission of infrared radiation?
Válasz
the greenhouse effect
943. kártya
Kérdés
Which term describes an atmospheric infrared-absorbing gas?
Válasz
a greenhouse gas
944. kártya
Kérdés
Which term describes the long-lived greenhouse gas strongly increased by fossil fuels?
Válasz
carbon dioxide (CO₂)
945. kártya
Kérdés
Which term describes the potent short-lived greenhouse gas from biological and fossil sources?
Válasz
methane (CH₄)
946. kártya
Kérdés
What is albedo?
Válasz
The fraction of incoming radiation reflected by a surface.
947. kártya
Kérdés
What is a carbon sink?
Válasz
A reservoir that absorbs more carbon than it releases over a specified period.
948. kártya
Kérdés
What is ocean acidification?
Válasz
Decline in seawater pH caused mainly by absorption of human-emitted carbon dioxide.
949. kártya
Kérdés
What is climate change?
Válasz
A persistent change in the statistical patterns of climate over decades or longer.
950. kártya
Kérdés
Which term describes surface reflectivity?
Válasz
albedo
951. kártya
Kérdés
Which term describes a reservoir with net carbon uptake?
Válasz
a carbon sink
952. kártya
Kérdés
Which term describes seawater pH decline from absorbed carbon dioxide?
Válasz
ocean acidification
953. kártya
Kérdés
Which term describes long-term change in climate patterns?
Válasz
climate change
954. kártya
Kérdés
What is the enhanced greenhouse effect?
Válasz
Additional warming caused by human-driven increases in greenhouse-gas concentrations.
955. kártya
Kérdés
How do climate mitigation and climate adaptation differ?
Válasz
Mitigation limits the magnitude of climate change; adaptation reduces harm from changes that occur.
956. kártya
Kérdés
How does increasing greenhouse-gas concentration alter Earth's energy balance?
Válasz
Less outgoing infrared energy initially escapes to space, so the climate warms until energy balance is restored at a higher temperature.
957. kártya
Kérdés
How can melting ice amplify warming?
Válasz
Less bright ice lowers albedo, so darker land or water absorbs more solar energy and causes further warming.
958. kártya
Kérdés
How can climate change alter species distributions?
Válasz
Temperature, rainfall, seasons, sea level, and interactions shift, moving or shrinking areas with suitable conditions.
959. kártya
Kérdés
Why can ocean acidification harm calcifying organisms?
Válasz
Carbonate chemistry changes, reducing availability of carbonate ions used to build calcium-carbonate structures.
960. kártya
Kérdés
How can ecosystem protection contribute to climate mitigation?
Válasz
Protecting forests, wetlands, soils, and coastal habitats can avoid emissions and maintain or increase carbon storage.
960 kártya
IB Biology SL Flashcards: Complete Course Review
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