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.
Про цю колоду
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.
Картки в цій колоді
Картка 1
Питання
What is water polarity?
Відповідь
The unequal sharing of electrons in a water molecule, giving oxygen a partial negative charge and the hydrogens partial positive charges.
Картка 2
Питання
What is a hydrogen bond?
Відповідь
A weak attraction between a partially positive hydrogen atom and a partially negative atom in another molecule.
Картка 3
Питання
What is cohesion?
Відповідь
Attraction between molecules of the same substance.
Картка 4
Питання
What is adhesion?
Відповідь
Attraction between molecules of different substances.
Картка 5
Питання
Which term describes unequal charge distribution within a water molecule?
Відповідь
water polarity
Картка 6
Питання
Which term describes the intermolecular attraction that links neighboring water molecules?
Відповідь
a hydrogen bond
Картка 7
Питання
Which term describes attraction between molecules of the same substance?
Відповідь
cohesion
Картка 8
Питання
Which term describes attraction between water and a different material?
Відповідь
adhesion
Картка 9
Питання
What is a solvent?
Відповідь
A liquid that dissolves solutes to form a solution.
Картка 10
Питання
What is specific heat capacity?
Відповідь
The energy required to raise the temperature of a unit mass of a substance by one degree.
Картка 11
Питання
What is latent heat of vaporization?
Відповідь
The energy required to vaporize a specified amount of liquid without changing its temperature.
Картка 12
Питання
Why does ice float on liquid water?
Відповідь
Hydrogen bonds hold water molecules in an open lattice in ice, making ice less dense than liquid water.
Картка 13
Питання
Which term describes a liquid that dissolves solutes?
Відповідь
a solvent
Картка 14
Питання
Which term describes the energy needed to raise a unit mass by one degree?
Відповідь
specific heat capacity
Картка 15
Питання
Which term describes the energy needed to vaporize a liquid without a temperature change?
Відповідь
latent heat of vaporization
Картка 16
Питання
Which property of water makes sweating an effective cooling mechanism?
Відповідь
Water absorbs substantial energy as it evaporates; the highest-energy molecules leave, carrying heat away from the skin.
Картка 17
Питання
Why does water resist rapid temperature change?
Відповідь
Many hydrogen bonds must absorb energy before molecular motion increases substantially, giving water a high specific heat capacity.
Картка 18
Питання
How do cohesion and adhesion support water transport in narrow tubes?
Відповідь
Cohesion keeps water molecules connected, while adhesion helps the water column cling to the tube wall.
Картка 19
Питання
How does water participate differently in hydrolysis and condensation?
Відповідь
Hydrolysis consumes water to split a bond; condensation forms a bond and releases water.
Картка 20
Питання
How does floating ice protect aquatic life in winter?
Відповідь
Surface ice insulates the liquid water below, slowing further heat loss and preventing the whole body of water from freezing rapidly.
Картка 21
Питання
Why is water effective for transporting many biological solutes?
Відповідь
Its polarity allows ions and other polar molecules to become surrounded and dispersed in solution.
Картка 22
Питання
Why do nonpolar substances tend to cluster in water?
Відповідь
Clustering reduces the nonpolar surface exposed to water, allowing more water molecules to maintain hydrogen-bond interactions.
Картка 23
Питання
What is a nucleotide?
Відповідь
A nucleic-acid monomer made of a pentose sugar, a phosphate group, and a nitrogenous base.
Картка 24
Питання
What is a nucleoside?
Відповідь
A nitrogenous base joined to a pentose sugar, without a phosphate group.
Картка 25
Питання
What is a phosphodiester bond?
Відповідь
A covalent bond linking the phosphate of one nucleotide to the sugar of the next nucleotide.
Картка 26
Питання
What is DNA?
Відповідь
A usually double-stranded nucleic acid that stores hereditary information in its base sequence.
Картка 27
Питання
Which term describes a sugar-phosphate-base monomer?
Відповідь
a nucleotide
Картка 28
Питання
Which term describes a base joined to a sugar but no phosphate?
Відповідь
a nucleoside
Картка 29
Питання
Which term describes the covalent linkage in a nucleic-acid sugar-phosphate backbone?
Відповідь
a phosphodiester bond
Картка 30
Питання
Which term describes the nucleic acid that usually stores hereditary information?
Відповідь
DNA
Картка 31
Питання
What is RNA?
Відповідь
A usually single-stranded nucleic acid involved in expressing and regulating genetic information.
Картка 32
Питання
What are antiparallel DNA strands?
Відповідь
Two DNA strands that run in opposite 5′ to 3′ directions.
Картка 33
Питання
What is complementary base pairing?
Відповідь
Specific pairing in which adenine pairs with thymine in DNA, or uracil in RNA, and cytosine pairs with guanine.
Картка 34
Питання
What is a purine?
Відповідь
A nitrogenous base with two fused rings; adenine and guanine are purines.
Картка 35
Питання
Which term describes the usually single-stranded nucleic acid used in gene expression?
Відповідь
RNA
Картка 36
Питання
Which term describes DNA strands running in opposite directions?
Відповідь
antiparallel DNA strands
Картка 37
Питання
Which term describes specific A–T or A–U and C–G pairing?
Відповідь
complementary base pairing
Картка 38
Питання
Which term describes a two-ring nitrogenous base?
Відповідь
a purine
Картка 39
Питання
What is a pyrimidine?
Відповідь
A nitrogenous base with one ring; cytosine, thymine, and uracil are pyrimidines.
Картка 40
Питання
What is a genome?
Відповідь
The complete genetic material of an organism or cell.
Картка 41
Питання
What three structural features commonly distinguish RNA from DNA?
Відповідь
RNA usually contains ribose, uses uracil instead of thymine, and is single-stranded rather than double-stranded.
Картка 42
Питання
What determines the base sequence of the second DNA strand?
Відповідь
Complementary base-pairing rules determine it: A pairs with T, and C pairs with G.
Картка 43
Питання
Which term describes a one-ring nitrogenous base?
Відповідь
a pyrimidine
Картка 44
Питання
Which term describes the complete genetic material of an organism?
Відповідь
a genome
Картка 45
Питання
What do the 5′ and 3′ labels of a nucleic-acid strand refer to?
Відповідь
They refer to numbered carbon atoms in the pentose sugar and define the strand's chemical direction.
Картка 46
Питання
Where is genetic information encoded in DNA?
Відповідь
In the order of nitrogenous bases along the DNA strand.
Картка 47
Питання
Why is ATP classified as a nucleotide?
Відповідь
It contains adenine, ribose, and phosphate groups, the three component types of a nucleotide.
Картка 48
Питання
How do mRNA, tRNA, and rRNA contribute to protein synthesis?
Відповідь
mRNA carries the coding sequence, tRNA delivers amino acids, and rRNA forms the catalytic and structural core of ribosomes.
Картка 49
Питання
How are a gene and a chromosome related?
Відповідь
A gene is a DNA sequence with a biological function; a chromosome is one long DNA molecule containing many genes and other sequences.
Картка 50
Питання
What happens to double-stranded DNA when it is denatured by heat?
Відповідь
Hydrogen bonds between complementary bases break and the two strands separate; the covalent backbones usually remain intact.
Картка 51
Питання
Why can each DNA strand serve as a template during replication?
Відповідь
Its base sequence determines a complementary sequence through specific base pairing.
Картка 52
Питання
In which direction are new nucleic-acid strands synthesized?
Відповідь
Nucleotides are added to the 3′ end, so synthesis proceeds 5′ to 3′.
Картка 53
Питання
What is a monosaccharide?
Відповідь
A single sugar unit that can serve as a carbohydrate monomer.
Картка 54
Питання
What is a disaccharide?
Відповідь
A carbohydrate formed from two monosaccharides joined by a glycosidic bond.
Картка 55
Питання
What is a polysaccharide?
Відповідь
A polymer made from many monosaccharide units.
Картка 56
Питання
What is a glycosidic bond?
Відповідь
A covalent bond joining monosaccharides in a carbohydrate.
Картка 57
Питання
Which term describes a single sugar unit?
Відповідь
a monosaccharide
Картка 58
Питання
Which term describes two monosaccharides joined together?
Відповідь
a disaccharide
Картка 59
Питання
Which term describes a polymer of many sugar units?
Відповідь
a polysaccharide
Картка 60
Питання
Which term describes the covalent linkage between monosaccharides?
Відповідь
a glycosidic bond
Картка 61
Питання
What is a triglyceride?
Відповідь
A lipid formed from glycerol joined to three fatty acids.
Картка 62
Питання
What is a fatty acid?
Відповідь
A hydrocarbon chain with a carboxyl group that can form part of many lipids.
Картка 63
Питання
What is a saturated fatty acid?
Відповідь
A fatty acid with no carbon-carbon double bonds in its hydrocarbon chain.
Картка 64
Питання
What is a phospholipid?
Відповідь
An amphipathic lipid with a phosphate-containing hydrophilic head and hydrophobic fatty-acid tails.
Картка 65
Питання
Which term describes glycerol joined to three fatty acids?
Відповідь
a triglyceride
Картка 66
Питання
Which term describes a hydrocarbon chain ending in a carboxyl group?
Відповідь
a fatty acid
Картка 67
Питання
Which term describes a fatty acid without carbon-carbon double bonds?
Відповідь
a saturated fatty acid
Картка 68
Питання
Which term describes a lipid with a polar head and nonpolar tails?
Відповідь
a phospholipid
Картка 69
Питання
How is a glycosidic bond formed between two monosaccharides?
Відповідь
A condensation reaction joins them and releases a molecule of water.
Картка 70
Питання
How is a polysaccharide broken into smaller sugars?
Відповідь
Hydrolysis adds water across glycosidic bonds, splitting the polymer.
Картка 71
Питання
Which polysaccharides store glucose in plants and animals?
Відповідь
Starch stores glucose in plants; glycogen stores glucose in animals and fungi.
Картка 72
Питання
Why is cellulose suitable for plant cell walls?
Відповідь
Its straight β-glucose chains hydrogen-bond into strong microfibrils that resist stretching.
Картка 73
Питання
Why do lipids store more energy per gram than carbohydrates?
Відповідь
Lipids contain more energy-rich carbon-hydrogen bonds and are more reduced.
Картка 74
Питання
Why do phospholipids form bilayers in water?
Відповідь
Hydrophilic heads interact with water while hydrophobic tails cluster away from water.
Картка 75
Питання
Besides energy storage, what are three biological roles of lipids?
Відповідь
They form membranes, provide thermal insulation and cushioning, and can act as signaling molecules.
Картка 76
Питання
How do cis double bonds affect fatty-acid packing and melting point?
Відповідь
They introduce bends that reduce close packing, usually lowering the melting point.
Картка 77
Питання
What is an amino acid?
Відповідь
A protein monomer with an amino group, a carboxyl group, a hydrogen, and a variable R group attached to a central carbon.
Картка 78
Питання
What is a peptide bond?
Відповідь
The covalent bond formed between the amino group of one amino acid and the carboxyl group of another.
Картка 79
Питання
What is a polypeptide?
Відповідь
A chain of amino acids joined by peptide bonds.
Картка 80
Питання
What is protein primary structure?
Відповідь
The amino-acid sequence of a polypeptide.
Картка 81
Питання
Which term describes a protein monomer with amino, carboxyl, and variable R groups?
Відповідь
an amino acid
Картка 82
Питання
Which term describes the covalent linkage between amino acids?
Відповідь
a peptide bond
Картка 83
Питання
Which term describes a chain of peptide-linked amino acids?
Відповідь
a polypeptide
Картка 84
Питання
Which term describes a protein's amino-acid sequence?
Відповідь
protein primary structure
Картка 85
Питання
What is protein secondary structure?
Відповідь
Local folding such as α-helices and β-sheets stabilized mainly by backbone hydrogen bonds.
Картка 86
Питання
What is protein tertiary structure?
Відповідь
The overall three-dimensional shape of one polypeptide produced by interactions among R groups and the backbone.
Картка 87
Питання
What is protein quaternary structure?
Відповідь
The arrangement of multiple polypeptide subunits in one functional protein.
Картка 88
Питання
What is protein denaturation?
Відповідь
Loss of a protein's normal three-dimensional shape and therefore usually its function.
Картка 89
Питання
Which term describes local α-helix and β-sheet folding?
Відповідь
protein secondary structure
Картка 90
Питання
Which term describes the overall three-dimensional shape of one polypeptide?
Відповідь
protein tertiary structure
Картка 91
Питання
Which term describes the association of multiple polypeptide subunits?
Відповідь
protein quaternary structure
Картка 92
Питання
Which term describes loss of a protein's native shape?
Відповідь
protein denaturation
Картка 93
Питання
What mainly gives different amino acids their different chemical properties?
Відповідь
Their variable R groups.
Картка 94
Питання
What reaction forms a peptide bond?
Відповідь
A condensation reaction releases water as the amino and carboxyl groups join.
Картка 95
Питання
Why can high temperature denature a protein?
Відповідь
Increased molecular motion disrupts weak interactions that maintain the protein's shape.
Картка 96
Питання
Why can extreme pH denature a protein?
Відповідь
It changes the charges of R groups and disrupts ionic and hydrogen-bond interactions.
Картка 97
Питання
How do fibrous and globular proteins generally differ?
Відповідь
Fibrous proteins are elongated and mainly structural; globular proteins are compact and often perform dynamic functions.
Картка 98
Питання
Why is three-dimensional shape crucial to protein function?
Відповідь
It creates specific binding, catalytic, structural, or interaction surfaces.
Картка 99
Питання
Name four broad biological roles of proteins.
Відповідь
Catalysis, transport, signaling, defense, movement, and structural support are major roles; any four are sufficient.
Картка 100
Питання
How can changing one amino acid alter protein function?
Відповідь
The substitution can change R-group interactions, folding, stability, or an active or binding site.
Картка 101
Питання
What is cell theory?
Відповідь
The principles that living organisms are made of cells, cells are the basic units of life, and cells arise from pre-existing cells.
Картка 102
Питання
What is a prokaryotic cell?
Відповідь
A cell without a nucleus or other membrane-bound organelles.
Картка 103
Питання
What is a eukaryotic cell?
Відповідь
A cell with DNA enclosed in a nucleus and with membrane-bound organelles.
Картка 104
Питання
What is the nucleus?
Відповідь
The double-membrane organelle that contains most of a eukaryotic cell's DNA.
Картка 105
Питання
Which term describes the principles describing cells as life's basic units?
Відповідь
cell theory
Картка 106
Питання
Which term describes a cell lacking a nucleus and membrane-bound organelles?
Відповідь
a prokaryotic cell
Картка 107
Питання
Which term describes a cell with a nucleus and membrane-bound organelles?
Відповідь
a eukaryotic cell
Картка 108
Питання
Which term describes the organelle containing most eukaryotic DNA?
Відповідь
the nucleus
Картка 109
Питання
What is a ribosome?
Відповідь
A molecular complex of rRNA and proteins that synthesizes polypeptides.
Картка 110
Питання
What is the cytoplasm?
Відповідь
The material inside the plasma membrane but outside the nucleus, including cytosol and organelles.
Картка 111
Питання
What is the plasma membrane?
Відповідь
The selectively permeable boundary separating a cell from its environment.
Картка 112
Питання
What is a cell wall?
Відповідь
A rigid extracellular layer that supports and protects cells in plants, fungi, and most prokaryotes.
Картка 113
Питання
Which term describes the complex that synthesizes polypeptides?
Відповідь
a ribosome
Картка 114
Питання
Which term describes cell contents inside the plasma membrane but outside the nucleus?
Відповідь
the cytoplasm
Картка 115
Питання
Which term describes the selectively permeable cell boundary?
Відповідь
the plasma membrane
Картка 116
Питання
Which term describes a rigid extracellular support layer?
Відповідь
a cell wall
Картка 117
Питання
What is the nucleoid?
Відповідь
The non-membrane-bound region containing the main chromosome of a prokaryotic cell.
Картка 118
Питання
What is the cytoskeleton?
Відповідь
A dynamic network of protein filaments involved in cell shape, transport, division, and movement.
Картка 119
Питання
What structures are shared by all cells?
Відповідь
A plasma membrane, cytoplasm, genetic material, and ribosomes.
Картка 120
Питання
Which structures distinguish a typical plant cell from a typical animal cell?
Відповідь
A plant cell has a cellulose wall, chloroplasts in photosynthetic tissues, and a large central vacuole; an animal cell lacks these.
Картка 121
Питання
Which term describes the prokaryotic chromosome-containing region?
Відповідь
the nucleoid
Картка 122
Питання
Which term describes the internal network of protein filaments?
Відповідь
the cytoskeleton
Картка 123
Питання
How is genetic material commonly organized in a prokaryotic cell?
Відповідь
The main DNA is usually one circular chromosome in the nucleoid, often accompanied by smaller plasmids.
Картка 124
Питання
How is microscope magnification calculated?
Відповідь
Magnification = image size ÷ actual size, using the same units.
Картка 125
Питання
What does microscope resolution describe?
Відповідь
The ability to distinguish two close points as separate.
Картка 126
Питання
Arrange these from smallest to largest: ribosome, bacterium, animal cell.
Відповідь
Ribosome, bacterium, animal cell.
Картка 127
Питання
How does the cytoskeleton support intracellular transport?
Відповідь
Motor proteins move vesicles and other cargo along cytoskeletal filaments.
Картка 128
Питання
Why does a small cell usually exchange materials more efficiently than a geometrically similar large cell?
Відповідь
It has a larger surface-area-to-volume ratio, providing more exchange surface per unit of cell contents.
Картка 129
Питання
Why is a cell more than a collection of isolated molecules?
Відповідь
Organized interactions among components produce emergent functions such as metabolism, regulation, and reproduction.
Картка 130
Питання
What major advantage do membrane-bound organelles give eukaryotic cells?
Відповідь
They separate incompatible reactions and create specialized local conditions.
Картка 131
Питання
What is a phospholipid bilayer?
Відповідь
A double layer of phospholipids with hydrophilic heads facing water and hydrophobic tails facing inward.
Картка 132
Питання
What is the fluid mosaic model?
Відповідь
A model describing membranes as mobile phospholipids containing a changing mosaic of proteins and other components.
Картка 133
Питання
What is an integral membrane protein?
Відповідь
A protein embedded in the bilayer, often spanning it.
Картка 134
Питання
What is a peripheral membrane protein?
Відповідь
A protein attached to a membrane surface rather than embedded in the bilayer.
Картка 135
Питання
Which term describes a double phospholipid layer with inward-facing tails?
Відповідь
a phospholipid bilayer
Картка 136
Питання
Which term describes the model of a mobile lipid layer containing varied proteins?
Відповідь
the fluid mosaic model
Картка 137
Питання
Which term describes a protein embedded within the lipid bilayer?
Відповідь
an integral membrane protein
Картка 138
Питання
Which term describes a protein attached to a membrane surface?
Відповідь
a peripheral membrane protein
Картка 139
Питання
What is membrane cholesterol?
Відповідь
An amphipathic lipid that buffers membrane fluidity and reduces permeability in animal cells.
Картка 140
Питання
What is a glycoprotein?
Відповідь
A protein with an attached carbohydrate chain, often used in recognition, adhesion, or signaling.
Картка 141
Питання
What is diffusion?
Відповідь
Net movement of particles from a region of higher concentration to lower concentration due to random motion.
Картка 142
Питання
What is osmosis?
Відповідь
Net movement of water across a selectively permeable membrane from higher water potential to lower water potential.
Картка 143
Питання
Which term describes the animal-membrane lipid that buffers fluidity?
Відповідь
membrane cholesterol
Картка 144
Питання
Which term describes a carbohydrate-bearing protein?
Відповідь
a glycoprotein
Картка 145
Питання
Which term describes net movement down a concentration gradient?
Відповідь
diffusion
Картка 146
Питання
Which term describes net water movement across a selectively permeable membrane?
Відповідь
osmosis
Картка 147
Питання
What is facilitated diffusion?
Відповідь
Passive movement down a gradient through a membrane channel or carrier protein.
Картка 148
Питання
What is active transport?
Відповідь
Energy-requiring movement of a substance against its concentration or electrochemical gradient.
Картка 149
Питання
Why is the phospholipid bilayer selectively permeable?
Відповідь
Its hydrophobic interior allows small nonpolar molecules through more readily than ions and most large or polar molecules.
Картка 150
Питання
How do simple diffusion and facilitated diffusion differ?
Відповідь
Both are passive, but facilitated diffusion uses specific membrane proteins while simple diffusion passes through the bilayer.
Картка 151
Питання
Which term describes passive transport through a channel or carrier?
Відповідь
facilitated diffusion
Картка 152
Питання
Which term describes energy-dependent transport against a gradient?
Відповідь
active transport
Картка 153
Питання
How do channel and carrier proteins differ?
Відповідь
Channels provide hydrophilic pores; carriers bind solutes and change shape to move them.
Картка 154
Питання
How can an ATP-driven pump maintain an ion gradient?
Відповідь
It couples ATP hydrolysis to a conformational change that moves ions against their electrochemical gradient.
Картка 155
Питання
How does endocytosis move material into a cell?
Відповідь
The plasma membrane folds inward and pinches off a vesicle containing the material.
Картка 156
Питання
How does exocytosis move material out of a cell?
Відповідь
An intracellular vesicle fuses with the plasma membrane and releases its contents outside.
Картка 157
Питання
What happens to an animal cell in a strongly hypotonic solution?
Відповідь
Water enters by osmosis; without a cell wall, the cell may swell and lyse.
Картка 158
Питання
Does molecular movement stop when diffusion reaches equilibrium?
Відповідь
No. Molecules continue moving randomly, but there is no net movement between regions.
Картка 159
Питання
How does decreasing temperature generally affect membrane fluidity?
Відповідь
It reduces phospholipid movement and makes the membrane less fluid.
Картка 160
Питання
Why do unsaturated fatty-acid tails increase membrane fluidity?
Відповідь
Their cis double-bond bends prevent phospholipids from packing tightly.
Картка 161
Питання
What changes increase the rate of simple diffusion across a membrane?
Відповідь
A steeper gradient, larger surface area, higher temperature, shorter distance, and greater membrane permeability increase the rate.
Картка 162
Питання
What is a mitochondrion?
Відповідь
A double-membrane organelle where most aerobic ATP production occurs.
Картка 163
Питання
What is a chloroplast?
Відповідь
A double-membrane organelle where photosynthesis occurs in plants and algae.
Картка 164
Питання
What is rough endoplasmic reticulum?
Відповідь
A membrane network bearing ribosomes that synthesizes and begins processing many secreted and membrane proteins.
Картка 165
Питання
What is smooth endoplasmic reticulum?
Відповідь
A membrane network involved in lipid synthesis, detoxification, and calcium storage.
Картка 166
Питання
Which term describes the main organelle of aerobic ATP production?
Відповідь
a mitochondrion
Картка 167
Питання
Which term describes the photosynthetic organelle of plants and algae?
Відповідь
a chloroplast
Картка 168
Питання
Which term describes the ribosome-studded membrane network?
Відповідь
rough endoplasmic reticulum
Картка 169
Питання
Which term describes the membrane network that lacks ribosomes and synthesizes lipids?
Відповідь
smooth endoplasmic reticulum
Картка 170
Питання
What is the Golgi apparatus?
Відповідь
Stacked membranes that modify, sort, and package proteins and lipids into vesicles.
Картка 171
Питання
What is a lysosome?
Відповідь
An acidic enzyme-containing organelle that digests macromolecules and worn cellular components.
Картка 172
Питання
What is a vesicle?
Відповідь
A small membrane-bound compartment used for transport, storage, or chemical reactions.
Картка 173
Питання
What is the central vacuole?
Відповідь
A large plant-cell compartment that stores solutes and helps maintain turgor pressure.
Картка 174
Питання
Which term describes the organelle that modifies and sorts cellular cargo?
Відповідь
the Golgi apparatus
Картка 175
Питання
Which term describes the acidic digestive organelle?
Відповідь
a lysosome
Картка 176
Питання
Which term describes a small membrane-bound transport compartment?
Відповідь
a vesicle
Картка 177
Питання
Which term describes the large plant compartment that supports turgor?
Відповідь
the central vacuole
Картка 178
Питання
Why can compartmentalization increase metabolic efficiency?
Відповідь
It concentrates enzymes and substrates, maintains suitable local conditions, and separates incompatible reactions.
Картка 179
Питання
How do mitochondrial cristae support ATP production?
Відповідь
They increase inner-membrane area for electron transport chains and ATP synthase.
Картка 180
Питання
Why are chloroplast thylakoids arranged as extensive membranes?
Відповідь
They provide a large surface for light-absorbing complexes, electron transport chains, and ATP synthase.
Картка 181
Питання
What is the main function of the nucleolus?
Відповідь
It produces rRNA and assembles ribosomal subunits.
Картка 182
Питання
Trace a secreted protein from synthesis to release.
Відповідь
Ribosome on rough ER → ER lumen → transport vesicle → Golgi apparatus → secretory vesicle → plasma membrane → exocytosis.
Картка 183
Питання
Why does a lysosome maintain an acidic interior?
Відповідь
Its hydrolytic enzymes work best at low pH, and acidity helps confine their activity from the cytosol.
Картка 184
Питання
How do the nucleus, ribosomes, ER, and Golgi cooperate in protein production?
Відповідь
DNA instructions are transcribed in the nucleus; ribosomes translate them; ER folds or modifies many products; Golgi further modifies and sorts them.
Картка 185
Питання
How are transport vesicles directed to the correct target membrane?
Відповідь
Specific recognition proteins on vesicles and target membranes interact, allowing selective docking and fusion.
Картка 186
Питання
What is cell differentiation?
Відповідь
The process by which a cell develops specialized structure and function.
Картка 187
Питання
What is a stem cell?
Відповідь
An unspecialized cell able to self-renew and produce differentiated cells.
Картка 188
Питання
What is gene expression?
Відповідь
Use of genetic information to produce a functional RNA or protein product.
Картка 189
Питання
What is a tissue?
Відповідь
A coordinated group of similar or related cells performing a shared function.
Картка 190
Питання
Which term describes development of specialized cell structure and function?
Відповідь
cell differentiation
Картка 191
Питання
Which term describes an unspecialized self-renewing cell?
Відповідь
a stem cell
Картка 192
Питання
Which term describes production of a functional product from genetic information?
Відповідь
gene expression
Картка 193
Питання
Which term describes a group of coordinated cells with a shared function?
Відповідь
a tissue
Картка 194
Питання
What is an organ?
Відповідь
A structure made of multiple tissues working together for particular functions.
Картка 195
Питання
What is the organ-system level of biological organization?
Відповідь
A group of organs that coordinate to perform major functions for an organism.
Картка 196
Питання
What is surface-area-to-volume ratio?
Відповідь
The amount of surface area available relative to the volume it must serve.
Картка 197
Питання
How can two specialized cells have the same genome but different structures?
Відповідь
They express different sets and amounts of genes, producing different proteins and cellular features.
Картка 198
Питання
Which term describes a structure composed of multiple tissue types?
Відповідь
an organ
Картка 199
Питання
Which term describes the level of biological organization formed by coordinated organs?
Відповідь
an organ system
Картка 200
Питання
Which term describes surface area available per unit volume?
Відповідь
surface-area-to-volume ratio
Картка 201
Питання
How is a mammalian red blood cell specialized for oxygen transport?
Відповідь
Its biconcave shape increases exchange area, it is flexible, and loss of its nucleus leaves more space for hemoglobin.
Картка 202
Питання
How is a sperm cell specialized for fertilization?
Відповідь
It has a flagellum for movement, many mitochondria for ATP, a haploid nucleus, and an acrosome containing enzymes.
Картка 203
Питання
How is a neuron specialized for rapid communication?
Відповідь
Long processes carry signals over distance, branching dendrites receive inputs, and synaptic terminals transmit signals to other cells.
Картка 204
Питання
How is a root hair cell specialized for mineral and water uptake?
Відповідь
Its long projection increases surface area, its thin wall shortens the pathway, and membrane transport proteins take up ions.
Картка 205
Питання
How is a palisade mesophyll cell specialized for photosynthesis?
Відповідь
It contains many chloroplasts and is positioned near the upper leaf surface where light is strongest.
Картка 206
Питання
How do ciliated epithelial cells help protect airways?
Відповідь
Their cilia move mucus containing trapped particles and microbes toward the throat.
Картка 207
Питання
Why can extreme specialization reduce a cell's independence?
Відповідь
Resources and structures are committed to a narrow role, so the cell depends on other cells for functions it no longer performs well.
Картка 208
Питання
What is water potential?
Відповідь
The potential energy of water per unit volume relative to pure water, used to predict the direction of water movement.
Картка 209
Питання
What is solute potential?
Відповідь
The negative contribution of dissolved solutes to water potential.
Картка 210
Питання
What is pressure potential?
Відповідь
The contribution of physical pressure to water potential.
Картка 211
Питання
What is turgor pressure?
Відповідь
Outward pressure of a plant-cell interior against its cell wall after water uptake.
Картка 212
Питання
Which term describes the tendency of water to move relative to pure water?
Відповідь
water potential
Картка 213
Питання
Which term describes the water-potential component lowered by dissolved solutes?
Відповідь
solute potential
Картка 214
Питання
Which term describes the water-potential component caused by physical pressure?
Відповідь
pressure potential
Картка 215
Питання
Which term describes pressure of plant-cell contents against the wall?
Відповідь
turgor pressure
Картка 216
Питання
What is plasmolysis?
Відповідь
Separation of the plasma membrane from the cell wall after a plant cell loses water.
Картка 217
Питання
What is a flaccid plant cell?
Відповідь
A plant cell with insufficient turgor pressure to be firm.
Картка 218
Питання
What is an isotonic condition?
Відповідь
A condition in which two solutions have equal effective water potential and no net water movement occurs.
Картка 219
Питання
In which direction does water move across a permeable membrane?
Відповідь
From higher water potential to lower water potential.
Картка 220
Питання
Which term describes membrane separation from the plant cell wall after water loss?
Відповідь
plasmolysis
Картка 221
Питання
Which term describes a plant cell lacking firm turgor?
Відповідь
a flaccid plant cell
Картка 222
Питання
Which term describes equal effective water potential across a membrane?
Відповідь
an isotonic condition
Картка 223
Питання
What is the water potential of pure water at standard pressure?
Відповідь
Zero; adding solute makes water potential more negative.
Картка 224
Питання
How are water potential, solute potential, and pressure potential related?
Відповідь
Water potential equals solute potential plus pressure potential: Ψ = Ψs + Ψp.
Картка 225
Питання
Why does a plant cell usually become turgid rather than burst in a hypotonic solution?
Відповідь
Water entry raises pressure potential, while the rigid cell wall resists further expansion.
Картка 226
Питання
What happens to a plant cell placed in a solution with much lower water potential?
Відповідь
Water leaves the cell, turgor falls, and severe loss can cause plasmolysis.
Картка 227
Питання
Can two solutions have different solute concentrations but equal water potential?
Відповідь
Yes. A difference in pressure potential can offset a difference in solute potential.
Картка 228
Питання
What is an enzyme?
Відповідь
A biological catalyst that increases reaction rate without being consumed.
Картка 229
Питання
What is an active site?
Відповідь
The region of an enzyme where substrate binds and catalysis occurs.
Картка 230
Питання
What is a substrate?
Відповідь
A reactant molecule on which an enzyme acts.
Картка 231
Питання
What is activation energy?
Відповідь
The minimum energy input needed for a reaction to begin.
Картка 232
Питання
Which term describes a biological catalyst?
Відповідь
an enzyme
Картка 233
Питання
Which term describes the substrate-binding catalytic region of an enzyme?
Відповідь
an active site
Картка 234
Питання
Which term describes a reactant bound and changed by an enzyme?
Відповідь
a substrate
Картка 235
Питання
Which term describes the energy barrier that must be overcome for a reaction?
Відповідь
activation energy
Картка 236
Питання
What is the induced-fit model?
Відповідь
The model in which substrate binding changes active-site shape to improve catalytic interactions.
Картка 237
Питання
What is enzyme denaturation?
Відповідь
Loss of the active three-dimensional shape of an enzyme, usually causing loss of activity.
Картка 238
Питання
What is competitive inhibition?
Відповідь
Inhibition caused by a molecule competing with substrate for the active site.
Картка 239
Питання
What is noncompetitive inhibition?
Відповідь
Inhibition caused by binding away from the active site and reducing catalytic function.
Картка 240
Питання
Which term describes the model where substrate binding reshapes the active site?
Відповідь
the induced-fit model
Картка 241
Питання
Which term describes loss of an enzyme's functional shape?
Відповідь
enzyme denaturation
Картка 242
Питання
Which term describes inhibition by active-site competition?
Відповідь
competitive inhibition
Картка 243
Питання
Which term describes inhibition by binding outside the active site?
Відповідь
noncompetitive inhibition
Картка 244
Питання
What is an enzyme optimum?
Відповідь
The condition, such as temperature or pH, at which an enzyme's activity is highest.
Картка 245
Питання
What is feedback inhibition?
Відповідь
Control in which a pathway product inhibits an enzyme acting earlier in the pathway.
Картка 246
Питання
How does an enzyme increase reaction rate?
Відповідь
It stabilizes the transition state and provides a pathway with lower activation energy.
Картка 247
Питання
Why does enzyme activity often rise and then fall as temperature increases?
Відповідь
Molecular collisions initially increase, but excessive heat disrupts enzyme shape and denatures the active site.
Картка 248
Питання
Which term describes the condition producing maximum enzyme activity?
Відповідь
an enzyme optimum
Картка 249
Питання
Which term describes pathway control by inhibition from an end product?
Відповідь
feedback inhibition
Картка 250
Питання
Why does each enzyme have a characteristic pH range?
Відповідь
pH changes the ionization of amino-acid side chains, affecting active-site shape and chemical interactions.
Картка 251
Питання
Why does increasing substrate concentration eventually stop increasing enzyme rate?
Відповідь
At saturation, nearly all active sites are occupied and enzyme concentration limits the maximum rate.
Картка 252
Питання
How does increasing enzyme concentration affect rate when substrate is abundant?
Відповідь
More active sites are available, so the initial rate increases roughly in proportion to enzyme concentration.
Картка 253
Питання
What gives an enzyme substrate specificity?
Відповідь
The active site's shape, charge, polarity, and chemical groups complement particular substrates and transition states.
Картка 254
Питання
What is one practical advantage of immobilizing an enzyme?
Відповідь
The enzyme can be separated from products and reused while conditions around it are controlled.
Картка 255
Питання
Does an enzyme change a reaction's equilibrium position?
Відповідь
No. It speeds forward and reverse reactions but does not change the equilibrium constant or final equilibrium position.
Картка 256
Питання
How can high substrate concentration reduce competitive inhibition?
Відповідь
More substrate molecules increase the chance that substrate rather than inhibitor occupies the active site.
Картка 257
Питання
Why are metabolic reactions commonly organized into pathways?
Відповідь
A sequence of enzyme-controlled steps allows energy changes and intermediates to be controlled and coupled.
Картка 258
Питання
What is ATP?
Відповідь
A nucleotide that transfers usable energy through coupling of its hydrolysis to cellular processes.
Картка 259
Питання
What is cellular respiration?
Відповідь
Controlled release of energy from organic molecules to produce ATP.
Картка 260
Питання
What is glycolysis?
Відповідь
A cytosolic pathway that splits glucose into two pyruvate molecules and yields a small amount of ATP and reduced electron carriers.
Картка 261
Питання
What is pyruvate?
Відповідь
The three-carbon product of glycolysis that can enter aerobic or anaerobic pathways.
Картка 262
Питання
Which term describes the cell's immediate phosphoryl-group energy carrier?
Відповідь
ATP
Картка 263
Питання
Which term describes controlled ATP-producing breakdown of organic molecules?
Відповідь
cellular respiration
Картка 264
Питання
Which term describes the cytosolic splitting of glucose into pyruvate?
Відповідь
glycolysis
Картка 265
Питання
Which term describes the three-carbon product of glycolysis?
Відповідь
pyruvate
Картка 266
Питання
What is aerobic respiration?
Відповідь
Respiration that uses oxygen as the final electron acceptor and produces much more ATP than fermentation.
Картка 267
Питання
What is anaerobic metabolism?
Відповідь
ATP-producing metabolism that proceeds without oxygen.
Картка 268
Питання
What is fermentation?
Відповідь
An anaerobic pathway that regenerates oxidized electron carriers so glycolysis can continue.
Картка 269
Питання
What is oxidation?
Відповідь
Loss of electrons, often accompanied in biology by loss of hydrogen or gain of oxygen.
Картка 270
Питання
Which term describes respiration using oxygen as final electron acceptor?
Відповідь
aerobic respiration
Картка 271
Питання
Which term describes ATP-producing metabolism without oxygen?
Відповідь
anaerobic metabolism
Картка 272
Питання
Which term describes anaerobic regeneration of electron carriers after glycolysis?
Відповідь
fermentation
Картка 273
Питання
Which term describes loss of electrons?
Відповідь
oxidation
Картка 274
Питання
What is reduction?
Відповідь
Gain of electrons, often accompanied in biology by gain of hydrogen or loss of oxygen.
Картка 275
Питання
What is a reduced electron carrier?
Відповідь
A molecule such as NADH that carries high-energy electrons and hydrogen from one reaction to another.
Картка 276
Питання
What is chemiosmosis?
Відповідь
ATP production driven by ions moving down an electrochemical gradient through ATP synthase.
Картка 277
Питання
What is the overall word equation for aerobic respiration of glucose?
Відповідь
Glucose + oxygen → carbon dioxide + water + energy transferred to ATP and heat.
Картка 278
Питання
Which term describes gain of electrons?
Відповідь
reduction
Картка 279
Питання
Which term describes a molecule carrying high-energy electrons between reactions?
Відповідь
a reduced electron carrier
Картка 280
Питання
Which term describes ATP production powered by an ion gradient?
Відповідь
chemiosmosis
Картка 281
Питання
Where does glycolysis occur?
Відповідь
In the cytosol.
Картка 282
Питання
What major stages of aerobic respiration occur in mitochondria?
Відповідь
Pyruvate oxidation and the citric acid cycle occur in the matrix; electron transport and chemiosmosis occur at the inner membrane.
Картка 283
Питання
What is oxygen's direct role in aerobic respiration?
Відповідь
It accepts electrons and hydrogen ions at the end of the electron transport chain, forming water.
Картка 284
Питання
Why does aerobic respiration yield much more ATP per glucose than fermentation?
Відповідь
It transfers electrons through an electron transport chain and uses oxidative phosphorylation, extracting far more of glucose's energy.
Картка 285
Питання
What is the purpose of lactate formation in oxygen-limited animal cells?
Відповідь
It regenerates NAD⁺ so glycolysis can continue producing a small amount of ATP.
Картка 286
Питання
What products are formed during alcoholic fermentation in yeast?
Відповідь
Ethanol and carbon dioxide, while NAD⁺ is regenerated.
Картка 287
Питання
Why is some energy released by respiration transferred as heat rather than captured in ATP?
Відповідь
Energy conversions are not fully efficient, so part of the chemical energy becomes disordered molecular motion.
Картка 288
Питання
What is substrate-level phosphorylation?
Відповідь
Direct transfer of a phosphate group from a metabolic intermediate to ADP to form ATP.
Картка 289
Питання
How does electron transport lead to ATP synthesis in mitochondria?
Відповідь
Electron energy pumps protons across the inner membrane; proton flow back through ATP synthase drives ATP formation.
Картка 290
Питання
Why can intense exercise increase lactate production?
Відповідь
ATP demand can exceed oxygen delivery and aerobic capacity, so cells regenerate NAD⁺ through lactate formation to sustain glycolysis.
Картка 291
Питання
What is photosynthesis?
Відповідь
Conversion of light energy into chemical energy used to synthesize organic molecules from carbon dioxide.
Картка 292
Питання
What is chlorophyll?
Відповідь
A green pigment that absorbs light energy for photosynthesis.
Картка 293
Питання
What is an absorption spectrum?
Відповідь
A graph showing how strongly a pigment absorbs different wavelengths of light.
Картка 294
Питання
What is an action spectrum?
Відповідь
A graph showing the rate or effectiveness of photosynthesis at different wavelengths.
Картка 295
Питання
Which term describes light-driven synthesis of organic molecules from carbon dioxide?
Відповідь
photosynthesis
Картка 296
Питання
Which term describes the principal green photosynthetic pigment?
Відповідь
chlorophyll
Картка 297
Питання
Which term describes a graph of pigment absorption versus wavelength?
Відповідь
an absorption spectrum
Картка 298
Питання
Which term describes a graph of photosynthetic effectiveness versus wavelength?
Відповідь
an action spectrum
Картка 299
Питання
What is photolysis of water?
Відповідь
Light-driven splitting of water that supplies electrons and hydrogen ions and releases oxygen.
Картка 300
Питання
What are light-dependent reactions?
Відповідь
Photosynthetic reactions that use light to generate ATP and reduced electron carriers while releasing oxygen.
Картка 301
Питання
What is the Calvin cycle?
Відповідь
A set of chloroplast reactions that uses ATP and reduced electron carriers to convert carbon dioxide into carbohydrate precursors.
Картка 302
Питання
What is carbon fixation?
Відповідь
Incorporation of inorganic carbon dioxide into an organic molecule.
Картка 303
Питання
Which term describes light-driven splitting of water?
Відповідь
photolysis of water
Картка 304
Питання
Which term describes photosynthetic reactions that directly capture light energy?
Відповідь
light-dependent reactions
Картка 305
Питання
Which term describes the carbon-reduction cycle of photosynthesis?
Відповідь
the Calvin cycle
Картка 306
Питання
Which term describes incorporation of carbon dioxide into organic matter?
Відповідь
carbon fixation
Картка 307
Питання
What is the role of a stoma in photosynthesis?
Відповідь
A pore in the leaf epidermis that regulates carbon-dioxide entry as well as water loss.
Картка 308
Питання
What is a limiting factor of photosynthesis?
Відповідь
The environmental factor whose availability currently restricts the photosynthetic rate.
Картка 309
Питання
What is the light compensation point?
Відповідь
The light intensity at which photosynthetic carbon uptake equals respiratory carbon release.
Картка 310
Питання
What is the overall word equation for oxygenic photosynthesis?
Відповідь
Carbon dioxide + water → carbohydrate + oxygen, using light energy.
Картка 311
Питання
Which term describes the regulated leaf pore controlling carbon-dioxide entry for photosynthesis?
Відповідь
a stoma
Картка 312
Питання
Which term describes the factor currently restricting photosynthetic rate?
Відповідь
a limiting factor
Картка 313
Питання
Which term describes the light level where photosynthesis and respiration balance?
Відповідь
the light compensation point
Картка 314
Питання
Where do the main stages of photosynthesis occur in a chloroplast?
Відповідь
Light-dependent reactions occur in thylakoid membranes; carbon-fixation reactions occur in the stroma.
Картка 315
Питання
What energy conversion occurs during photosynthesis?
Відповідь
Light energy is converted into chemical energy stored first in ATP and reduced carriers and ultimately in organic molecules.
Картка 316
Питання
From which reactant does the oxygen released by photosynthesis originate?
Відповідь
Water.
Картка 317
Питання
What role does RuBisCO play in photosynthesis?
Відповідь
It catalyzes fixation of carbon dioxide by adding it to an organic acceptor molecule.
Картка 318
Питання
What tradeoff is controlled when stomata open?
Відповідь
Opening permits carbon dioxide entry but increases water loss by transpiration.
Картка 319
Питання
Name three leaf features that support photosynthesis.
Відповідь
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.
Картка 320
Питання
What can a plant do with carbohydrate made by photosynthesis?
Відповідь
Use it in respiration, convert it to storage or structural carbohydrates, or use its carbon to make lipids, amino acids, and other molecules.
Картка 321
Питання
How are products of the light-dependent reactions used in carbon fixation?
Відповідь
ATP supplies energy and NADPH supplies reducing power for conversion of fixed carbon into carbohydrate precursors.
Картка 322
Питання
Why does increasing light intensity eventually stop increasing photosynthetic rate?
Відповідь
Another factor, such as carbon dioxide supply, temperature, or biochemical capacity, becomes limiting.
Картка 323
Питання
How can increasing carbon dioxide concentration affect photosynthetic rate?
Відповідь
It can increase the rate until another factor becomes limiting.
Картка 324
Питання
Why does photosynthetic rate usually have a temperature optimum?
Відповідь
Enzyme-controlled reactions accelerate with temperature up to an optimum, then decline as enzymes and membranes lose effective function.
Картка 325
Питання
Why does an action spectrum broadly resemble the combined absorption spectra of photosynthetic pigments?
Відповідь
Wavelengths absorbed by the pigments supply more energy for photosynthesis than poorly absorbed wavelengths.
Картка 326
Питання
What is semiconservative replication?
Відповідь
DNA replication in which each daughter molecule contains one parental strand and one newly synthesized strand.
Картка 327
Питання
What is DNA helicase?
Відповідь
An enzyme that unwinds the double helix and separates the strands by disrupting base pairing.
Картка 328
Питання
What is DNA polymerase?
Відповідь
An enzyme that adds nucleotides to a growing DNA strand using a template.
Картка 329
Питання
What is a primer?
Відповідь
A short nucleic-acid segment providing a free 3′ end from which DNA polymerase can extend.
Картка 330
Питання
Which term describes replication producing one old and one new strand per DNA molecule?
Відповідь
semiconservative replication
Картка 331
Питання
Which term describes the enzyme that separates DNA strands?
Відповідь
DNA helicase
Картка 332
Питання
Which term describes the enzyme that builds DNA from a template?
Відповідь
DNA polymerase
Картка 333
Питання
Which term describes the short segment providing a starting 3′ end?
Відповідь
a primer
Картка 334
Питання
What is the leading strand?
Відповідь
The new DNA strand synthesized continuously toward the replication fork.
Картка 335
Питання
What is the lagging strand?
Відповідь
The new DNA strand synthesized discontinuously away from the replication fork.
Картка 336
Питання
What is an Okazaki fragment?
Відповідь
A short DNA segment synthesized on the lagging strand.
Картка 337
Питання
What is DNA ligase?
Відповідь
An enzyme that seals breaks in the sugar-phosphate backbone, joining DNA fragments.
Картка 338
Питання
Which term describes the continuously synthesized daughter strand?
Відповідь
the leading strand
Картка 339
Питання
Which term describes the discontinuously synthesized daughter strand?
Відповідь
the lagging strand
Картка 340
Питання
Which term describes a short newly made segment of lagging-strand DNA?
Відповідь
an Okazaki fragment
Картка 341
Питання
Which term describes the enzyme that joins DNA fragments by sealing the backbone?
Відповідь
DNA ligase
Картка 342
Питання
How does complementary base pairing ensure accurate DNA copying?
Відповідь
Each template base specifies the nucleotide added opposite it: A pairs with T, and C pairs with G.
Картка 343
Питання
Why does DNA polymerase synthesize DNA only 5′ to 3′?
Відповідь
It can add a nucleotide only to the free 3′ hydroxyl group of the growing strand.
Картка 344
Питання
When in the cell cycle is nuclear DNA replicated?
Відповідь
During S phase of interphase, before cell division.
Картка 345
Питання
How can a replication error become a permanent mutation?
Відповідь
If it escapes proofreading and repair, the altered sequence can be copied in later cell generations.
Картка 346
Питання
Why are leading and lagging strands synthesized differently?
Відповідь
The templates are antiparallel while DNA polymerase works only 5′ to 3′, forcing one strand to be made discontinuously.
Картка 347
Питання
How do proofreading and repair reduce replication errors?
Відповідь
Incorrectly paired nucleotides are recognized, removed, and replaced before or after replication continues.
Картка 348
Питання
What three repeating steps amplify DNA in PCR?
Відповідь
Strand separation by heating, primer annealing during cooling, and DNA extension by a heat-stable polymerase.
Картка 349
Питання
What determines which DNA region PCR amplifies?
Відповідь
The sequences and positions of the two primers flanking the target region.
Картка 350
Питання
What is transcription?
Відповідь
Synthesis of RNA from a DNA template.
Картка 351
Питання
What is RNA polymerase?
Відповідь
The enzyme that synthesizes RNA complementary to a DNA template strand.
Картка 352
Питання
What is messenger RNA?
Відповідь
RNA carrying a coding sequence from DNA to ribosomes.
Картка 353
Питання
What is a codon?
Відповідь
A three-base sequence in mRNA that specifies an amino acid or a translation signal.
Картка 354
Питання
Which term describes RNA synthesis from DNA?
Відповідь
transcription
Картка 355
Питання
Which term describes the enzyme that builds RNA from a DNA template?
Відповідь
RNA polymerase
Картка 356
Питання
Which term describes RNA that carries coding information to ribosomes?
Відповідь
messenger RNA
Картка 357
Питання
Which term describes a three-base mRNA unit?
Відповідь
a codon
Картка 358
Питання
What is translation?
Відповідь
Synthesis of a polypeptide using the codon sequence of mRNA.
Картка 359
Питання
What does a ribosome do during translation?
Відповідь
It reads mRNA and catalyzes polypeptide synthesis using its rRNA-protein machinery.
Картка 360
Питання
What is transfer RNA?
Відповідь
RNA that carries a specific amino acid and pairs its anticodon with an mRNA codon.
Картка 361
Питання
What is an anticodon?
Відповідь
A three-base tRNA sequence complementary to an mRNA codon.
Картка 362
Питання
Which term describes polypeptide synthesis from an mRNA sequence?
Відповідь
translation
Картка 363
Питання
Which term describes the translation complex that reads mRNA and builds a polypeptide?
Відповідь
a ribosome
Картка 364
Питання
Which term describes the adaptor RNA carrying an amino acid?
Відповідь
transfer RNA
Картка 365
Питання
Which term describes the tRNA triplet that pairs with a codon?
Відповідь
an anticodon
Картка 366
Питання
What is the genetic code?
Відповідь
The set of rules relating mRNA codons to amino acids and translation signals.
Картка 367
Питання
What are start and stop codons?
Відповідь
mRNA signals that establish the reading frame or terminate translation.
Картка 368
Питання
Where do transcription and translation occur in a eukaryotic cell?
Відповідь
Transcription occurs in the nucleus; translation occurs on ribosomes in the cytoplasm or on rough ER.
Картка 369
Питання
How is an mRNA sequence related to its DNA template strand?
Відповідь
It is complementary and antiparallel, with uracil in RNA opposite adenine in DNA.
Картка 370
Питання
Which term describes the codon-to-amino-acid rule set?
Відповідь
the genetic code
Картка 371
Питання
Which term describes codons that begin or end translation?
Відповідь
start and stop codons
Картка 372
Питання
What reaction does the ribosome catalyze as a polypeptide grows?
Відповідь
Formation of peptide bonds between adjacent amino acids.
Картка 373
Питання
What does it mean that the genetic code is degenerate?
Відповідь
Most amino acids are specified by more than one codon.
Картка 374
Питання
How can one mRNA produce many polypeptides quickly?
Відповідь
Multiple ribosomes can translate the same mRNA simultaneously as a polyribosome.
Картка 375
Питання
Why is translation not the final step in producing many functional proteins?
Відповідь
The polypeptide must fold and may undergo cleavage, chemical modification, or assembly with other subunits.
Картка 376
Питання
How does mRNA compare with the DNA coding strand?
Відповідь
It has the same base sequence except that RNA contains uracil where DNA contains thymine.
Картка 377
Питання
What happens during eukaryotic RNA splicing?
Відповідь
Introns are removed and exons are joined to form mature mRNA.
Картка 378
Питання
Why must codons be read in the correct reading frame?
Відповідь
Changing the starting position changes every downstream triplet and therefore the amino-acid sequence.
Картка 379
Питання
How is the correct amino acid matched to each mRNA codon?
Відповідь
Each tRNA is charged with a particular amino acid, and its anticodon pairs with the complementary codon.
Картка 380
Питання
How can a base substitution affect a protein?
Відповідь
It may be silent, change one amino acid, create a stop codon, or sometimes alter RNA processing.
Картка 381
Питання
What is a mutation?
Відповідь
A change in a DNA sequence or chromosome structure that can be passed to daughter cells.
Картка 382
Питання
What is a base substitution?
Відповідь
Replacement of one nucleotide pair by another.
Картка 383
Питання
What is an insertion mutation?
Відповідь
Addition of one or more nucleotides to a DNA sequence.
Картка 384
Питання
What is a deletion mutation?
Відповідь
Loss of one or more nucleotides from a DNA sequence.
Картка 385
Питання
Which term describes a lasting DNA-sequence or chromosome change?
Відповідь
a mutation
Картка 386
Питання
Which term describes replacement of one DNA base pair?
Відповідь
a base substitution
Картка 387
Питання
Which term describes addition of nucleotides to DNA?
Відповідь
an insertion mutation
Картка 388
Питання
Which term describes loss of nucleotides from DNA?
Відповідь
a deletion mutation
Картка 389
Питання
What is a frameshift mutation?
Відповідь
A coding-sequence insertion or deletion not divisible by three that changes downstream codon grouping.
Картка 390
Питання
What is a silent mutation?
Відповідь
A sequence change that does not alter the encoded amino acid.
Картка 391
Питання
What is a missense mutation?
Відповідь
A mutation that changes a codon so a different amino acid is incorporated.
Картка 392
Питання
What is a nonsense mutation?
Відповідь
A mutation that changes an amino-acid codon into a stop codon.
Картка 393
Питання
Which term describes a mutation that shifts downstream codon grouping?
Відповідь
a frameshift mutation
Картка 394
Питання
Which term describes a coding change that leaves the amino acid unchanged?
Відповідь
a silent mutation
Картка 395
Питання
Which term describes a mutation causing one amino-acid substitution?
Відповідь
a missense mutation
Картка 396
Питання
Which term describes a mutation creating a premature stop codon?
Відповідь
a nonsense mutation
Картка 397
Питання
How do germline and somatic mutations differ in inheritance?
Відповідь
Germline mutations can enter gametes and be inherited; somatic mutations affect a cell lineage within the individual.
Картка 398
Питання
What can cause mutations?
Відповідь
Replication errors, spontaneous chemical changes, radiation, and mutagenic chemicals can alter DNA.
Картка 399
Питання
How does DNA repair protect genome stability?
Відповідь
Repair systems detect damaged or mismatched DNA and restore the correct structure or sequence when possible.
Картка 400
Питання
Why are mutations essential to evolution despite often being neutral or harmful?
Відповідь
They create new alleles, providing the heritable variation on which selection and drift act.
Картка 401
Питання
What is the basic role of guide RNA in CRISPR gene editing?
Відповідь
It directs a nuclease to a complementary DNA sequence.
Картка 402
Питання
Why can the same type of DNA mutation have effects ranging from none to severe?
Відповідь
Effects depend on location, genetic-code redundancy, protein role, cell type, and environmental context.
Картка 403
Питання
How can accumulated mutations contribute to cancer?
Відповідь
Mutations can activate growth-promoting genes or disable genes that restrain division, repair DNA, or trigger cell death.
Картка 404
Питання
Why can repairing a CRISPR-induced DNA break produce different editing outcomes?
Відповідь
Different cellular repair pathways may disrupt the target sequence or use a supplied template for a specific change.
Картка 405
Питання
What is an off-target effect in gene editing?
Відповідь
An unintended DNA change at a site sufficiently similar to the intended target.
Картка 406
Питання
Why does heritable human genome editing raise additional ethical concerns?
Відповідь
Changes could pass to future generations who cannot consent, with uncertain long-term biological and social effects.
Картка 407
Питання
What is the cell cycle?
Відповідь
The ordered sequence of cell growth, DNA replication, nuclear division, and cell division.
Картка 408
Питання
What is interphase?
Відповідь
The period of growth, normal activity, and DNA replication between nuclear divisions.
Картка 409
Питання
What is mitosis?
Відповідь
Nuclear division that usually produces genetically equivalent daughter nuclei.
Картка 410
Питання
What is cytokinesis?
Відповідь
Division of the cytoplasm to form separate daughter cells.
Картка 411
Питання
Which term describes the ordered sequence from one cell division to the next?
Відповідь
the cell cycle
Картка 412
Питання
Which term describes the growth and DNA-replication period between divisions?
Відповідь
interphase
Картка 413
Питання
Which term describes division producing genetically equivalent nuclei?
Відповідь
mitosis
Картка 414
Питання
Which term describes physical division of the cytoplasm?
Відповідь
cytokinesis
Картка 415
Питання
What is a chromosome?
Відповідь
One DNA molecule packaged with associated proteins.
Картка 416
Питання
What are sister chromatids?
Відповідь
The two replicated copies of a chromosome joined before separation.
Картка 417
Питання
What is a centromere?
Відповідь
The chromosome region that holds sister chromatids together and organizes kinetochore attachment.
Картка 418
Питання
What is the mitotic spindle?
Відповідь
A microtubule system that attaches to and separates chromosomes during cell division.
Картка 419
Питання
Which term describes a protein-packaged DNA molecule?
Відповідь
a chromosome
Картка 420
Питання
Which term describes joined replicated copies of one chromosome?
Відповідь
sister chromatids
Картка 421
Питання
Which term describes the chromosome region joining sister chromatids?
Відповідь
a centromere
Картка 422
Питання
Which term describes the chromosome-separating microtubule system?
Відповідь
the mitotic spindle
Картка 423
Питання
What is the basic sequence of mitosis?
Відповідь
Chromosomes condense, align at the cell equator, sister chromatids separate to opposite poles, and new nuclei form.
Картка 424
Питання
Why must DNA replicate before mitosis?
Відповідь
Each chromosome must have two copies so each daughter nucleus can receive a complete genome.
Картка 425
Питання
Why are daughter cells from mitosis usually genetically similar?
Відповідь
Replicated sister chromatids are separated so each daughter receives one copy of every chromosome.
Картка 426
Питання
What are major roles of mitosis in multicellular organisms?
Відповідь
Growth, tissue repair, cell replacement, and some forms of asexual reproduction.
Картка 427
Питання
How do homologous chromosomes differ from sister chromatids?
Відповідь
Homologs carry the same gene loci but may have different alleles; sister chromatids are replicated copies of one chromosome.
Картка 428
Питання
What key outcome distinguishes mitosis from meiosis?
Відповідь
Mitosis usually preserves chromosome number and similarity; meiosis halves chromosome number and generates genetically varied haploid cells.
Картка 429
Питання
How does cytokinesis commonly occur in animal cells?
Відповідь
A contractile ring tightens the plasma membrane into a cleavage furrow.
Картка 430
Питання
How does cytokinesis commonly occur in plant cells?
Відповідь
Vesicles fuse at the center to form a cell plate that develops into new membranes and a cell wall.
Картка 431
Питання
What is the purpose of cell-cycle checkpoints?
Відповідь
They delay progression when conditions are unsuitable or DNA and chromosome attachment are defective.
Картка 432
Питання
How is loss of cell-cycle control related to cancer?
Відповідь
Cells can divide despite damage or growth restraints, producing an expanding abnormal clone.
Картка 433
Питання
What is a gene?
Відповідь
A DNA sequence that contributes to a functional product and influences a characteristic or cellular process.
Картка 434
Питання
What is an allele?
Відповідь
One of the alternative DNA-sequence forms at a gene locus.
Картка 435
Питання
What is a gene locus?
Відповідь
The physical position of a gene on a chromosome.
Картка 436
Питання
What is a genotype?
Відповідь
The allele combination of an organism at one or more loci.
Картка 437
Питання
Which term describes a functional DNA sequence?
Відповідь
a gene
Картка 438
Питання
Which term describes an alternative form of a gene?
Відповідь
an allele
Картка 439
Питання
Which term describes a gene's chromosome position?
Відповідь
a gene locus
Картка 440
Питання
Which term describes an organism's allele combination?
Відповідь
a genotype
Картка 441
Питання
What is a phenotype?
Відповідь
An observable or measurable trait produced by genotype and environment.
Картка 442
Питання
What is homozygous?
Відповідь
Having two identical alleles at a diploid locus.
Картка 443
Питання
What is heterozygous?
Відповідь
Having two different alleles at a diploid locus.
Картка 444
Питання
What is a dominant allele?
Відповідь
An allele expressed in the phenotype of a heterozygote under a specified inheritance model.
Картка 445
Питання
Which term describes an observable trait resulting from genes and environment?
Відповідь
a phenotype
Картка 446
Питання
Which term describes having two identical alleles at a locus?
Відповідь
homozygous
Картка 447
Питання
Which term describes having two different alleles at a locus?
Відповідь
heterozygous
Картка 448
Питання
Which term describes an allele expressed in a heterozygote?
Відповідь
a dominant allele
Картка 449
Питання
What is a recessive allele?
Відповідь
An allele whose phenotype is masked by a dominant allele in a heterozygote.
Картка 450
Питання
What is a genetic carrier?
Відповідь
An unaffected heterozygote who can transmit a recessive disease allele.
Картка 451
Питання
What is a test cross?
Відповідь
A cross with a homozygous recessive individual used to infer an unknown dominant phenotype's genotype.
Картка 452
Питання
What is a pedigree?
Відповідь
A diagram showing biological relationships and occurrence of a trait across generations.
Картка 453
Питання
Which term describes an allele masked in a heterozygote?
Відповідь
a recessive allele
Картка 454
Питання
Which term describes an unaffected heterozygote carrying a recessive disease allele?
Відповідь
a genetic carrier
Картка 455
Питання
Which term describes a cross used to reveal an unknown dominant genotype?
Відповідь
a test cross
Картка 456
Питання
Which term describes a family diagram tracking a trait across generations?
Відповідь
a pedigree
Картка 457
Питання
What does allele segregation mean during gamete formation?
Відповідь
The two alleles at a diploid locus separate so each gamete receives one.
Картка 458
Питання
What does a Punnett square predict?
Відповідь
Expected genotype and phenotype probabilities from specified parental gametes, not guaranteed family outcomes.
Картка 459
Питання
What phenotypic ratio is expected from Aa × Aa with complete dominance?
Відповідь
Approximately 3 dominant phenotype : 1 recessive phenotype.
Картка 460
Питання
What genotypic ratio is expected from Aa × Aa?
Відповідь
1 AA : 2 Aa : 1 aa.
Картка 461
Питання
What happens in codominance?
Відповідь
Both alleles contribute distinctly to the heterozygous phenotype.
Картка 462
Питання
What happens in incomplete dominance?
Відповідь
The heterozygote has a phenotype intermediate between the two homozygotes.
Картка 463
Питання
How can environment affect phenotype without changing genotype?
Відповідь
Conditions alter development, physiology, or gene expression, changing the observed trait.
Картка 464
Питання
What is the ultimate source of new alleles?
Відповідь
Mutation.
Картка 465
Питання
Why are X-linked recessive traits more common in XY individuals?
Відповідь
They have only one X chromosome, so one recessive allele on it can determine the phenotype.
Картка 466
Питання
When is the product rule used in genetic probability?
Відповідь
For independent events that must both occur; multiply their probabilities.
Картка 467
Питання
When is the sum rule used in genetic probability?
Відповідь
For mutually exclusive alternative outcomes; add their probabilities.
Картка 468
Питання
Why do polygenic traits often show continuous variation?
Відповідь
Many loci contribute small effects, creating many possible genotypes and phenotypes, often further influenced by environment.
Картка 469
Питання
What pedigree pattern can suggest an autosomal recessive trait?
Відповідь
Unaffected parents can have affected children, and all sexes are affected at similar frequencies.
Картка 470
Питання
What is a species?
Відповідь
A group of organisms whose members can potentially interbreed and produce fertile offspring under natural conditions.
Картка 471
Питання
What is binomial nomenclature?
Відповідь
The two-part scientific naming system using a genus name followed by a specific epithet.
Картка 472
Питання
What is taxonomy?
Відповідь
The naming and classification of organisms.
Картка 473
Питання
What is a biological domain?
Відповідь
The broadest commonly used taxonomic rank, separating Bacteria, Archaea, and Eukarya.
Картка 474
Питання
Which term describes a naturally interbreeding group producing fertile offspring?
Відповідь
a species
Картка 475
Питання
Which term describes the genus-plus-specific-epithet naming system?
Відповідь
binomial nomenclature
Картка 476
Питання
Which term describes the science of naming and classifying organisms?
Відповідь
taxonomy
Картка 477
Питання
Which term describes the broadest common taxonomic rank?
Відповідь
a biological domain
Картка 478
Питання
What is biodiversity?
Відповідь
Variation of life at genetic, species, and ecosystem levels.
Картка 479
Питання
What is an autotroph?
Відповідь
An organism that makes organic compounds from inorganic carbon using light or chemical energy.
Картка 480
Питання
What is a heterotroph?
Відповідь
An organism that obtains organic carbon by consuming other organisms or their products.
960 карток
IB Biology SL Flashcards: Complete Course Review
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Картка 481
Питання
What is a unicellular organism?
Відповідь
An organism consisting of one cell that carries out all essential life functions.
Картка 482
Питання
Which term describes variation of life across genes, species, and ecosystems?
Відповідь
biodiversity
Картка 483
Питання
Which term describes an organism that builds organic matter from inorganic carbon?
Відповідь
an autotroph
Картка 484
Питання
Which term describes an organism obtaining organic carbon from other organisms?
Відповідь
a heterotroph
Картка 485
Питання
Which term describes an organism made of one cell?
Відповідь
a unicellular organism
Картка 486
Питання
What is a multicellular organism?
Відповідь
An organism composed of many cooperating cells, often with specialized cell types.
Картка 487
Питання
What is a karyotype?
Відповідь
An ordered display of chromosomes used to examine their number and large-scale structure.
Картка 488
Питання
What broad feature distinguishes both Bacteria and Archaea from Eukarya?
Відповідь
Their cells lack a nucleus and other membrane-bound organelles.
Картка 489
Питання
What features characterize most plant cells?
Відповідь
Cellulose walls, chloroplasts in photosynthetic tissues, and large vacuoles are typical features.
Картка 490
Питання
Which term describes an organism made of many cooperating cells?
Відповідь
a multicellular organism
Картка 491
Питання
Which term describes an ordered display of an individual's chromosomes?
Відповідь
a karyotype
Картка 492
Питання
How do fungi obtain nutrients?
Відповідь
They secrete digestive enzymes and absorb soluble products; their cells usually have chitin-containing walls.
Картка 493
Питання
What distinguishes animal nutrition and cell structure?
Відповідь
Animals ingest organic material, and their cells lack cell walls and chloroplasts.
Картка 494
Питання
Why are scientific names useful across languages?
Відповідь
A standardized name identifies the same organism internationally and reduces ambiguity from local common names.
Картка 495
Питання
Why can genetic diversity improve a population's resilience?
Відповідь
More heritable variation increases the chance that some individuals tolerate new diseases or environmental changes.
Картка 496
Питання
What does ecosystem diversity measure?
Відповідь
The variety of habitats, communities, and ecological processes within a region.
Картка 497
Питання
Why are Archaea classified separately from Bacteria?
Відповідь
They differ in genetic sequences, membrane chemistry, cell-wall composition, and aspects of molecular machinery.
Картка 498
Питання
Why is the biological species concept difficult to apply to fossils or asexual organisms?
Відповідь
Their ability to interbreed and produce fertile offspring cannot be tested in the usual way.
Картка 499
Питання
Does a larger chromosome number necessarily mean a more complex organism?
Відповідь
No. Chromosome number varies through fusion, fission, and duplication and does not directly measure biological complexity.
Картка 500
Питання
Does genome size reliably predict organismal complexity?
Відповідь
No. Large amounts of noncoding and repeated DNA make genome size a poor simple measure of complexity.
Картка 501
Питання
What evidence can be combined when classifying organisms?
Відповідь
Molecular sequences, cell structure, anatomy, development, physiology, and reproductive evidence can all contribute.
Картка 502
Питання
What is gas exchange?
Відповідь
Diffusion of respiratory gases between an organism and its environment or transport fluid.
Картка 503
Питання
What is ventilation?
Відповідь
Bulk movement of air or water over a gas-exchange surface.
Картка 504
Питання
What is an alveolus?
Відповідь
A microscopic air sac in the lung where gases diffuse between air and blood.
Картка 505
Питання
What is pulmonary surfactant?
Відповідь
A substance lining alveoli that lowers surface tension and reduces collapse.
Картка 506
Питання
Which term describes diffusion of oxygen and carbon dioxide across a respiratory surface?
Відповідь
gas exchange
Картка 507
Питання
Which term describes bulk movement of respiratory medium over an exchange surface?
Відповідь
ventilation
Картка 508
Питання
Which term describes a microscopic lung air sac?
Відповідь
an alveolus
Картка 509
Питання
Which term describes the alveolar lining that lowers surface tension?
Відповідь
pulmonary surfactant
Картка 510
Питання
What is the diaphragm?
Відповідь
A sheet of skeletal muscle whose contraction increases thoracic volume during inhalation.
Картка 511
Питання
What is tidal volume?
Відповідь
The volume of air moved in or out during a normal breath.
Картка 512
Питання
What is a stoma?
Відповідь
A regulated epidermal pore through which gases diffuse in leaves.
Картка 513
Питання
What is countercurrent exchange?
Відповідь
Exchange between fluids moving in opposite directions, maintaining a gradient along most of the surface.
Картка 514
Питання
Which term describes the muscle sheet that expands the thorax during inhalation?
Відповідь
the diaphragm
Картка 515
Питання
Which term describes air volume moved in one normal breath?
Відповідь
tidal volume
Картка 516
Питання
Which term describes a regulated leaf gas-exchange pore?
Відповідь
a stoma
Картка 517
Питання
Which term describes opposite fluid flow that maintains an exchange gradient?
Відповідь
countercurrent exchange
Картка 518
Питання
What features make an efficient gas-exchange surface?
Відповідь
Large area, short diffusion distance, permeability, and maintained concentration gradients.
Картка 519
Питання
How is a steep oxygen gradient maintained across alveoli?
Відповідь
Ventilation replenishes alveolar oxygen and blood flow removes absorbed oxygen.
Картка 520
Питання
How does diaphragm contraction cause inhalation?
Відповідь
Thoracic volume increases, lung pressure falls below atmospheric pressure, and air flows inward.
Картка 521
Питання
What drives quiet exhalation?
Відповідь
The diaphragm relaxes and elastic recoil reduces thoracic and lung volume, raising pressure and pushing air out.
Картка 522
Питання
Why do ventilation rate and depth increase during exercise?
Відповідь
They increase oxygen uptake and carbon dioxide removal to support higher cellular respiration.
Картка 523
Питання
How does leaf structure shorten the pathway for carbon dioxide diffusion?
Відповідь
Stomata open into air spaces, and mesophyll cells expose moist surfaces close to those spaces.
Картка 524
Питання
Why does carbon dioxide diffuse from tissues into blood?
Відповідь
Respiring cells produce carbon dioxide, making its partial pressure higher in tissues than in incoming blood.
Картка 525
Питання
How does countercurrent flow improve oxygen uptake at fish gills?
Відповідь
Blood continually meets water with a higher oxygen concentration, preserving diffusion along the lamella.
Картка 526
Питання
Why does closing stomata reduce both water loss and photosynthesis?
Відповідь
It limits water-vapor diffusion out but also restricts carbon dioxide diffusion into the leaf.
Картка 527
Питання
What is a circulatory system?
Відповідь
A transport system that moves a fluid carrying gases, nutrients, wastes, hormones, and heat through an organism.
Картка 528
Питання
What is an artery?
Відповідь
A blood vessel carrying blood away from the heart under relatively high pressure.
Картка 529
Питання
What is a vein?
Відповідь
A blood vessel carrying blood toward the heart, usually with low pressure and often valves.
Картка 530
Питання
What is a capillary?
Відповідь
A microscopic thin-walled vessel where substances exchange between blood and tissues.
Картка 531
Питання
Which term describes an internal fluid-transport system?
Відповідь
a circulatory system
Картка 532
Питання
Which term describes a vessel carrying blood away from the heart?
Відповідь
an artery
Картка 533
Питання
Which term describes a vessel carrying blood toward the heart?
Відповідь
a vein
Картка 534
Питання
Which term describes a microscopic exchange blood vessel?
Відповідь
a capillary
Картка 535
Питання
What is the cardiac cycle?
Відповідь
The repeating sequence of heart-chamber contraction and relaxation that pumps blood.
Картка 536
Питання
What is hemoglobin?
Відповідь
An iron-containing protein in red blood cells that binds oxygen reversibly.
Картка 537
Питання
What is xylem?
Відповідь
Plant vascular tissue that transports water and mineral ions and provides structural support.
Картка 538
Питання
What is phloem?
Відповідь
Plant vascular tissue that transports sucrose and other organic solutes between sources and sinks.
Картка 539
Питання
Which term describes the repeating pumping sequence of the heart?
Відповідь
the cardiac cycle
Картка 540
Питання
Which term describes the oxygen-carrying protein of red blood cells?
Відповідь
hemoglobin
Картка 541
Питання
Which term describes plant tissue carrying water and minerals?
Відповідь
xylem
Картка 542
Питання
Which term describes plant tissue carrying organic solutes?
Відповідь
phloem
Картка 543
Питання
What is transpiration?
Відповідь
Loss of water vapor from plant surfaces, mainly through stomata.
Картка 544
Питання
What is phloem translocation?
Відповідь
Movement of organic solutes through phloem from sources to sinks.
Картка 545
Питання
How do a source and a sink differ in plant transport?
Відповідь
A source releases assimilates to phloem; a sink removes them for use or storage.
Картка 546
Питання
What makes human circulation a double circulation?
Відповідь
Blood passes through the heart once in the pulmonary circuit and again in the systemic circuit during one complete journey.
Картка 547
Питання
Which term describes water-vapor loss from plant surfaces?
Відповідь
transpiration
Картка 548
Питання
Which term describes movement of organic solutes through phloem?
Відповідь
phloem translocation
Картка 549
Питання
Which term describes the exporting and importing regions of phloem transport?
Відповідь
source and sink
Картка 550
Питання
How is an artery adapted to high pressure?
Відповідь
It has thick elastic and muscular walls and a relatively narrow lumen.
Картка 551
Питання
How is a vein adapted to return low-pressure blood?
Відповідь
It has a wide lumen, thinner walls, and valves that reduce backflow.
Картка 552
Питання
How does capillary structure support exchange?
Відповідь
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.
Картка 553
Питання
What determines whether a heart valve opens or closes?
Відповідь
Pressure differences across the valve.
Картка 554
Питання
Trace water from soil to the atmosphere through a plant.
Відповідь
Soil → root hairs → root tissues → xylem → leaf mesophyll → leaf air spaces → stomata → atmosphere.
Картка 555
Питання
Why may root cells use active transport to absorb mineral ions?
Відповідь
Ion concentrations can be lower in soil than in root cells, so uptake must occur against a gradient.
Картка 556
Питання
Why do large multicellular organisms need bulk transport systems?
Відповідь
Their low surface-area-to-volume ratio and long diffusion distances make diffusion alone too slow for whole-body supply.
Картка 557
Питання
Why does hemoglobin unload more oxygen in actively respiring tissues?
Відповідь
Lower oxygen and often higher carbon dioxide and acidity reduce hemoglobin's oxygen affinity.
Картка 558
Питання
How does transpiration pull water upward through xylem?
Відповідь
Evaporation lowers leaf water potential and creates tension; cohesion transmits the pull through the continuous water column.
Картка 559
Питання
How do wind and low humidity generally affect transpiration?
Відповідь
Both maintain a steep water-vapor gradient outside the leaf, increasing transpiration if stomata remain open.
Картка 560
Питання
What drives mass flow in phloem?
Відповідь
Sugar loading draws in water and raises pressure at a source; unloading lowers pressure at a sink, producing bulk flow.
Картка 561
Питання
Can the same plant organ be a source at one time and a sink at another?
Відповідь
Yes. A storage organ may import sugars while filling and export them later during growth or germination.
Картка 562
Питання
What is a neuron?
Відповідь
An excitable cell specialized to receive, process, and transmit information.
Картка 563
Питання
What is a sensory neuron?
Відповідь
A neuron carrying information from a receptor toward the central nervous system.
Картка 564
Питання
What is a motor neuron?
Відповідь
A neuron carrying commands from the central nervous system to an effector.
Картка 565
Питання
What is the resting potential?
Відповідь
The voltage difference across an unstimulated neuron's membrane, with the inside negative relative to outside.
Картка 566
Питання
Which term describes an excitable information-transmitting cell?
Відповідь
a neuron
Картка 567
Питання
Which term describes a neuron carrying receptor information to the CNS?
Відповідь
a sensory neuron
Картка 568
Питання
Which term describes a neuron carrying CNS commands to an effector?
Відповідь
a motor neuron
Картка 569
Питання
Which term describes the negative-inside voltage of an unstimulated neuron?
Відповідь
the resting potential
Картка 570
Питання
What is an action potential?
Відповідь
A brief, self-propagating reversal and restoration of membrane potential along an excitable membrane.
Картка 571
Питання
What is depolarization?
Відповідь
A change that makes membrane potential less negative, and during an action potential often positive.
Картка 572
Питання
What is repolarization?
Відповідь
Return of membrane potential toward its resting negative value after depolarization.
Картка 573
Питання
What is a synapse?
Відповідь
A junction where one cell communicates with another cell.
Картка 574
Питання
Which term describes a brief propagating change in neuron membrane voltage?
Відповідь
an action potential
Картка 575
Питання
Which term describes a membrane-voltage change toward a less negative value?
Відповідь
depolarization
Картка 576
Питання
Which term describes return toward resting membrane voltage?
Відповідь
repolarization
Картка 577
Питання
Which term describes a communication junction between cells?
Відповідь
a synapse
Картка 578
Питання
What is a neurotransmitter?
Відповідь
A chemical released by a neuron that changes the activity of a target cell.
Картка 579
Питання
What is the refractory period?
Відповідь
A brief period after an action potential when another is impossible or requires a stronger stimulus.
Картка 580
Питання
What is myelin?
Відповідь
An insulating sheath around some axons that speeds impulse conduction.
Картка 581
Питання
What happens when membrane depolarization reaches threshold?
Відповідь
Voltage-gated channels trigger the self-amplifying events of an action potential.
Картка 582
Питання
Which term describes a neuron-released signaling chemical?
Відповідь
a neurotransmitter
Картка 583
Питання
Which term describes the recovery interval after an action potential?
Відповідь
the refractory period
Картка 584
Питання
Which term describes the insulating axon sheath?
Відповідь
myelin
Картка 585
Питання
What does the all-or-none principle mean for an action potential?
Відповідь
Once threshold is reached, the action potential has a characteristic size; stronger stimuli increase frequency, not its amplitude.
Картка 586
Питання
How does myelin increase conduction speed?
Відповідь
Depolarizing current travels rapidly beneath myelin and action potentials regenerate mainly at gaps in the sheath.
Картка 587
Питання
What is the basic sequence at a chemical synapse?
Відповідь
An impulse triggers neurotransmitter release; it diffuses across the cleft, binds receptors, and alters the postsynaptic cell.
Картка 588
Питання
Why can a reflex response be rapid?
Відповідь
A short neural pathway produces an automatic response without waiting for conscious processing.
Картка 589
Питання
What is sensory transduction?
Відповідь
Conversion of a physical or chemical stimulus into an electrical signal in a receptor cell.
Картка 590
Питання
How does an action potential propagate along an axon?
Відповідь
Local current depolarizes the next membrane region to threshold, opening voltage-gated channels there.
Картка 591
Питання
Why does an action potential normally travel in one direction along an axon?
Відповідь
The membrane just behind it is refractory and cannot immediately fire again.
Картка 592
Питання
How is neurotransmitter action ended?
Відповідь
The transmitter is removed by enzymatic breakdown, reuptake, or diffusion away.
Картка 593
Питання
What is sensory adaptation?
Відповідь
Reduced receptor or neural response during a constant, unchanging stimulus.
Картка 594
Питання
How can a drug alter synaptic transmission?
Відповідь
It may mimic or block a transmitter, change its release, or change its removal from the synaptic cleft.
Картка 595
Питання
What is an organ system?
Відповідь
A group of organs coordinating to perform major functions for an organism.
Картка 596
Питання
What is a hormone?
Відповідь
A signaling molecule released into transport fluid and acting on target cells with suitable receptors.
Картка 597
Питання
What is an endocrine gland?
Відповідь
A gland that secretes hormones into extracellular fluid and blood rather than through a duct.
Картка 598
Питання
What is a hormone target cell?
Відповідь
A cell able to respond because it has the appropriate receptor.
Картка 599
Питання
Which term describes a coordinated group of organs?
Відповідь
an organ system
Картка 600
Питання
Which term describes a long-distance chemical messenger carried in body fluid?
Відповідь
a hormone
Картка 601
Питання
Which term describes a ductless hormone-secreting gland?
Відповідь
an endocrine gland
Картка 602
Питання
Which term describes a cell with a receptor for a particular hormone?
Відповідь
a hormone target cell
Картка 603
Питання
What is digestion?
Відповідь
Mechanical and chemical breakdown of food into molecules small enough to absorb.
Картка 604
Питання
What is absorption?
Відповідь
Movement of digested nutrients across an exchange surface into blood or lymph.
Картка 605
Питання
What is peristalsis?
Відповідь
Coordinated waves of smooth-muscle contraction that move material through the digestive tract.
Картка 606
Питання
What is an intestinal villus?
Відповідь
A finger-like projection increasing the absorptive surface of the small intestine.
Картка 607
Питання
Which term describes breakdown of food into absorbable molecules?
Відповідь
digestion
Картка 608
Питання
Which term describes movement of digested nutrients into transport fluids?
Відповідь
absorption
Картка 609
Питання
Which term describes wave-like gut contractions moving contents?
Відповідь
peristalsis
Картка 610
Питання
Which term describes a finger-like intestinal absorption projection?
Відповідь
an intestinal villus
Картка 611
Питання
What is excretion?
Відповідь
Removal of metabolic waste products from the body.
Картка 612
Питання
What is a nephron?
Відповідь
The microscopic functional unit of the kidney that filters blood and modifies filtrate into urine.
Картка 613
Питання
What is ultrafiltration?
Відповідь
Pressure-driven filtration of small molecules from blood into a kidney capsule while cells and most proteins remain in blood.
Картка 614
Питання
What is selective reabsorption?
Відповідь
Recovery of useful substances and regulated amounts of water and ions from kidney filtrate into blood.
Картка 615
Питання
Which term describes removal of metabolic wastes?
Відповідь
excretion
Картка 616
Питання
Which term describes the kidney's microscopic functional unit?
Відповідь
a nephron
Картка 617
Питання
Which term describes pressure filtration at the start of a nephron?
Відповідь
ultrafiltration
Картка 618
Питання
Which term describes return of useful substances from kidney filtrate to blood?
Відповідь
selective reabsorption
Картка 619
Питання
What is skeletal muscle?
Відповідь
Striated voluntary muscle attached to the skeleton and used for movement and posture.
Картка 620
Питання
What is an antagonistic muscle pair?
Відповідь
Two muscles producing opposite movements at a joint because muscles pull but do not push.
Картка 621
Питання
How do nervous and endocrine signaling generally differ?
Відповідь
Neural signals are rapid and targeted; hormonal signals are usually slower, longer-lasting, and distributed through body fluids.
Картка 622
Питання
Why does a circulating hormone affect only some cells?
Відповідь
Only target cells express receptors that recognize the hormone and activate a response.
Картка 623
Питання
Which term describes voluntary striated muscle that moves the skeleton?
Відповідь
skeletal muscle
Картка 624
Питання
Which term describes two muscles producing opposite joint movements?
Відповідь
an antagonistic muscle pair
Картка 625
Питання
What is the final absorbable product of most dietary carbohydrate digestion?
Відповідь
Monosaccharides, especially glucose.
Картка 626
Питання
What are the main absorbable products of protein digestion?
Відповідь
Amino acids and small peptides that are completed to amino acids during absorption.
Картка 627
Питання
How is the small intestine adapted for absorption?
Відповідь
Folds, villi, and microvilli increase area; a thin epithelium, rich blood supply, and lymph vessels support transport.
Картка 628
Питання
Name three integrative roles of the liver.
Відповідь
It processes absorbed nutrients, regulates blood chemistry, detoxifies substances, produces bile, and converts ammonia to urea; any three are sufficient.
Картка 629
Питання
Why are blood cells and most plasma proteins absent from normal kidney filtrate?
Відповідь
They are too large to cross the filtration barrier.
Картка 630
Питання
How do muscles move a bone at a joint?
Відповідь
Contraction shortens the muscle, pulling through a tendon on the bone.
Картка 631
Питання
Why are antagonistic muscles needed at many joints?
Відповідь
A muscle can pull in one direction but cannot push itself back, so an opposing muscle produces the reverse movement.
Картка 632
Питання
Why must organ systems be integrated rather than acting independently?
Відповідь
Each system depends on materials, signals, waste removal, and stable conditions supplied by other systems.
Картка 633
Питання
Why do many absorbed lipids enter lymph before blood?
Відповідь
Intestinal cells package them into lipoprotein particles too large to enter ordinary blood capillaries directly.
Картка 634
Питання
Why is glucose normally absent from final urine?
Відповідь
Filtered glucose is selectively reabsorbed into blood when transporter capacity is not exceeded.
Картка 635
Питання
How do respiratory, circulatory, and muscular systems cooperate during exercise?
Відповідь
Ventilation supplies oxygen, circulation transports gases and fuels, and muscles use ATP while returning carbon dioxide, heat, and metabolites.
Картка 636
Питання
How do liver, circulation, and kidneys cooperate in nitrogen-waste removal?
Відповідь
The liver converts toxic ammonia to urea, blood carries urea, and kidneys filter and excrete it.
Картка 637
Питання
What is a pathogen?
Відповідь
A biological agent capable of causing disease.
Картка 638
Питання
What is an antigen?
Відповідь
A molecule recognized specifically by an antibody or lymphocyte receptor.
Картка 639
Питання
What is innate immunity?
Відповідь
Rapid, nonspecific defense mechanisms present without prior exposure.
Картка 640
Питання
What is adaptive immunity?
Відповідь
Specific defense that develops through lymphocyte activation and can form memory.
Картка 641
Питання
Which term describes a disease-causing biological agent?
Відповідь
a pathogen
Картка 642
Питання
Which term describes a molecule specifically recognized by adaptive immune receptors?
Відповідь
an antigen
Картка 643
Питання
Which term describes rapid nonspecific immune defense?
Відповідь
innate immunity
Картка 644
Питання
Which term describes specific immune defense capable of memory?
Відповідь
adaptive immunity
Картка 645
Питання
What is a phagocyte?
Відповідь
A cell that engulfs and digests microbes, particles, or damaged cells.
Картка 646
Питання
What is a lymphocyte?
Відповідь
An adaptive immune cell with receptors specific to particular antigens.
Картка 647
Питання
What is an antibody?
Відповідь
A secreted immunoglobulin that binds a specific antigen.
Картка 648
Питання
What is a B lymphocyte?
Відповідь
A lymphocyte that can differentiate into antibody-secreting plasma cells and memory cells.
Картка 649
Питання
Which term describes an engulfing immune cell?
Відповідь
a phagocyte
Картка 650
Питання
Which term describes an antigen-specific adaptive immune cell?
Відповідь
a lymphocyte
Картка 651
Питання
Which term describes a secreted antigen-binding immunoglobulin?
Відповідь
an antibody
Картка 652
Питання
Which term describes the lymphocyte lineage that produces antibody-secreting cells?
Відповідь
a B lymphocyte
Картка 653
Питання
What is a helper T cell?
Відповідь
A lymphocyte that coordinates immune responses through contact signals and cytokines.
Картка 654
Питання
What is an immune memory cell?
Відповідь
A long-lived lymphocyte that responds rapidly after re-exposure to its antigen.
Картка 655
Питання
What is vaccination?
Відповідь
Deliberate exposure to a safe form or component of an antigen to generate protective immune memory.
Картка 656
Питання
What is an antibiotic?
Відповідь
A substance that kills bacteria or inhibits their growth at clinically useful doses.
Картка 657
Питання
Which term describes the T cell that coordinates other immune cells?
Відповідь
a helper T cell
Картка 658
Питання
Which term describes a long-lived lymphocyte enabling faster re-exposure response?
Відповідь
an immune memory cell
Картка 659
Питання
Which term describes safe antigen exposure used to create immune memory?
Відповідь
vaccination
Картка 660
Питання
Which term describes a drug acting against bacteria?
Відповідь
an antibiotic
Картка 661
Питання
What are examples of first-line defenses against pathogens?
Відповідь
Intact skin, mucus, cilia, antimicrobial secretions, stomach acidity, and competing microbiota.
Картка 662
Питання
How does inflammation help defend damaged tissue?
Відповідь
It increases local blood flow and vessel permeability and recruits immune cells and defensive molecules.
Картка 663
Питання
What happens during phagocytosis?
Відповідь
A cell surrounds a particle in a vesicle, then fuses it with digestive compartments to destroy or process it.
Картка 664
Питання
How can antibodies help eliminate a pathogen?
Відповідь
They can neutralize targets, block attachment, clump particles, and mark them for phagocytosis or complement attack.
Картка 665
Питання
Why can a vaccine generate protection without causing the full disease?
Відповідь
It presents antigen in a weakened, inactivated, partial, or encoded form that stimulates immunity with much lower risk.
Картка 666
Питання
Why do antibiotics not treat viral infections?
Відповідь
Viruses lack the bacterial structures and independent metabolic processes targeted by antibiotics.
Картка 667
Питання
What determines the antigen specificity of a lymphocyte?
Відповідь
The molecular shape and chemistry of its unique surface receptor.
Картка 668
Питання
What is clonal selection?
Відповідь
An antigen activates lymphocytes with matching receptors, causing them to proliferate and differentiate.
Картка 669
Питання
Why is a secondary adaptive immune response usually faster and stronger?
Відповідь
Memory cells are more numerous and activate rapidly, producing effective cells and antibodies sooner.
Картка 670
Питання
How can high vaccination coverage protect some unvaccinated people?
Відповідь
Reduced transmission makes encounters with infectious individuals less likely, though protection is incomplete and pathogen-dependent.
Картка 671
Питання
How does antibiotic use select for resistant bacteria?
Відповідь
Susceptible bacteria are removed while resistant variants survive and reproduce, increasing resistance-allele frequency.
Картка 672
Питання
Why can unnecessary or incomplete antibiotic exposure promote resistance?
Відповідь
It creates selection favoring resistant cells while potentially leaving surviving bacteria to multiply and spread.
Картка 673
Питання
What is an allergy?
Відповідь
An immune response to a normally harmless antigen that causes tissue symptoms or damage.
Картка 674
Питання
What is asexual reproduction?
Відповідь
Production of offspring from one parent without fusion of gametes.
Картка 675
Питання
What is sexual reproduction?
Відповідь
Production of offspring involving fusion of haploid gametes.
Картка 676
Питання
What is a gamete?
Відповідь
A haploid reproductive cell able to fuse with another gamete.
Картка 677
Питання
What is fertilization?
Відповідь
Fusion of gamete nuclei to form a diploid zygote.
Картка 678
Питання
Which term describes reproduction without gamete fusion?
Відповідь
asexual reproduction
Картка 679
Питання
Which term describes reproduction involving gamete fusion?
Відповідь
sexual reproduction
Картка 680
Питання
Which term describes a haploid reproductive cell?
Відповідь
a gamete
Картка 681
Питання
Which term describes fusion of gamete nuclei?
Відповідь
fertilization
Картка 682
Питання
What is a zygote?
Відповідь
The diploid cell formed by fertilization.
Картка 683
Питання
What is meiosis?
Відповідь
Cell division that halves chromosome number and usually produces genetically varied haploid cells.
Картка 684
Питання
What is ovulation?
Відповідь
Release of a secondary oocyte from an ovary.
Картка 685
Питання
What is implantation?
Відповідь
Attachment and embedding of an early embryo in the uterine lining.
Картка 686
Питання
Which term describes the first diploid cell after fertilization?
Відповідь
a zygote
Картка 687
Питання
Which term describes division producing varied haploid cells?
Відповідь
meiosis
Картка 688
Питання
Which term describes release of an oocyte from an ovary?
Відповідь
ovulation
Картка 689
Питання
Which term describes embedding of an early embryo in the uterine lining?
Відповідь
implantation
Картка 690
Питання
What is the placenta?
Відповідь
A temporary organ that exchanges materials between maternal and fetal blood supplies without normally mixing them directly.
Картка 691
Питання
What is pollination?
Відповідь
Transfer of pollen from an anther to a receptive stigma.
Картка 692
Питання
Why does sexual reproduction usually produce more genetic variation than asexual reproduction?
Відповідь
Meiosis reshuffles alleles and random fertilization combines genomes from two gametes.
Картка 693
Питання
Why must gametes be haploid?
Відповідь
Fusion of two haploid gametes restores the diploid chromosome number instead of doubling it each generation.
Картка 694
Питання
Which term describes the maternal-fetal exchange organ?
Відповідь
the placenta
Картка 695
Питання
Which term describes transfer of pollen to a stigma?
Відповідь
pollination
Картка 696
Питання
What are major roles of FSH in the ovarian cycle?
Відповідь
It stimulates follicle development and supports estrogen secretion.
Картка 697
Питання
What is a major role of the mid-cycle LH surge?
Відповідь
It triggers ovulation and formation of the corpus luteum.
Картка 698
Питання
How does estrogen contribute to the uterine cycle?
Відповідь
It promotes repair and thickening of the uterine lining after menstruation.
Картка 699
Питання
How does progesterone contribute to the uterine cycle?
Відповідь
It maintains a thick, secretory uterine lining after ovulation.
Картка 700
Питання
Where does human fertilization usually occur?
Відповідь
In an oviduct, before the early embryo reaches the uterus.
Картка 701
Питання
What happens after compatible pollen reaches a flower's stigma?
Відповідь
A pollen tube grows toward an ovule and delivers male nuclei for fertilization.
Картка 702
Питання
Why does menstruation usually begin if pregnancy does not occur?
Відповідь
The corpus luteum degenerates, progesterone and estrogen fall, and the uterine lining is no longer maintained.
Картка 703
Питання
What substances commonly cross the placenta between mother and fetus?
Відповідь
Oxygen and nutrients move toward the fetus; carbon dioxide and nitrogenous wastes move toward the mother.
Картка 704
Питання
How can contraception prevent pregnancy in different ways?
Відповідь
Methods can inhibit ovulation, block sperm from reaching an egg, prevent fertilization, or permanently interrupt the reproductive ducts.
Картка 705
Питання
What is homeostasis?
Відповідь
Maintenance of internal conditions within ranges compatible with normal function despite change.
Картка 706
Питання
What is negative feedback?
Відповідь
Control in which a deviation triggers responses that oppose the original change.
Картка 707
Питання
What is a set point?
Відповідь
The target value or range around which a regulated variable is maintained.
Картка 708
Питання
What is a homeostatic receptor?
Відповідь
A sensor that detects a change in a regulated variable.
Картка 709
Питання
Which term describes maintenance of a stable functional internal environment?
Відповідь
homeostasis
Картка 710
Питання
Which term describes feedback that counteracts a deviation?
Відповідь
negative feedback
Картка 711
Питання
Which term describes the target around which a variable is regulated?
Відповідь
a set point
Картка 712
Питання
Which term describes the sensor in a feedback system?
Відповідь
a homeostatic receptor
Картка 713
Питання
What is a control center?
Відповідь
The component that compares information with a target and coordinates a response.
Картка 714
Питання
What is an effector?
Відповідь
A muscle, gland, or other component that carries out a control response.
Картка 715
Питання
What is thermoregulation?
Відповідь
Control of body temperature within a functional range.
Картка 716
Питання
What is vasodilation?
Відповідь
Widening of blood vessels, often increasing blood flow near the skin.
Картка 717
Питання
Which term describes the feedback component that evaluates input and directs a response?
Відповідь
a control center
Картка 718
Питання
Which term describes the component that executes a physiological response?
Відповідь
an effector
Картка 719
Питання
Which term describes physiological regulation of body temperature?
Відповідь
thermoregulation
Картка 720
Питання
Which term describes widening of blood vessels?
Відповідь
vasodilation
Картка 721
Питання
What is vasoconstriction?
Відповідь
Narrowing of blood vessels, often reducing blood flow near the skin.
Картка 722
Питання
What is insulin?
Відповідь
A pancreatic hormone that lowers elevated blood glucose by promoting uptake and storage.
Картка 723
Питання
What is glucagon?
Відповідь
A pancreatic hormone that raises low blood glucose by promoting release of stored fuel.
Картка 724
Питання
What are the main components of a homeostatic feedback loop?
Відповідь
A regulated variable, receptor, control center, effectors, and responses that alter the variable.
Картка 725
Питання
Which term describes narrowing of blood vessels?
Відповідь
vasoconstriction
Картка 726
Питання
Which term describes the pancreatic hormone that lowers blood glucose?
Відповідь
insulin
Картка 727
Питання
Which term describes the pancreatic hormone that raises blood glucose?
Відповідь
glucagon
Картка 728
Питання
What happens when blood glucose rises after a meal?
Відповідь
Insulin secretion increases, promoting glucose uptake and storage so blood glucose falls toward its normal range.
Картка 729
Питання
What happens when blood glucose falls during fasting?
Відповідь
Glucagon secretion increases, promoting glycogen breakdown and glucose release by the liver.
Картка 730
Питання
How does sweating cool the body?
Відповідь
Evaporation of water from skin transfers heat to the environment.
Картка 731
Питання
How does skin vasodilation increase heat loss?
Відповідь
It brings more warm blood near the surface, increasing transfer of heat to the environment.
Картка 732
Питання
How does shivering warm the body?
Відповідь
Rapid involuntary muscle contractions increase respiration and heat production.
Картка 733
Питання
Does homeostasis keep internal conditions perfectly constant?
Відповідь
No. Variables fluctuate within controlled ranges around target values.
Картка 734
Питання
How does ADH help conserve water?
Відповідь
It increases water permeability in kidney collecting ducts, so more water is reabsorbed and urine becomes more concentrated.
Картка 735
Питання
How should ADH secretion change during dehydration?
Відповідь
It should increase, promoting greater water reabsorption by the kidneys.
Картка 736
Питання
How does positive feedback differ from negative feedback?
Відповідь
Positive feedback amplifies a change until an endpoint; negative feedback opposes a change and stabilizes a variable.
Картка 737
Питання
Why can diabetes mellitus cause persistently high blood glucose?
Відповідь
Insulin production may be insufficient or target cells may respond poorly to insulin.
Картка 738
Питання
What is biological evolution?
Відповідь
Change in heritable characteristics or allele frequencies of a population across generations.
Картка 739
Питання
What is allele frequency?
Відповідь
The proportion of gene copies in a population represented by a particular allele.
Картка 740
Питання
What is microevolution?
Відповідь
Evolutionary change in allele frequencies within populations over relatively short timescales.
Картка 741
Питання
What is speciation?
Відповідь
Evolutionary formation of new species.
Картка 742
Питання
Which term describes change in a population's heritable composition across generations?
Відповідь
biological evolution
Картка 743
Питання
Which term describes the proportion of a population's gene copies that are one allele?
Відповідь
allele frequency
Картка 744
Питання
Which term describes short-timescale allele-frequency change within populations?
Відповідь
microevolution
Картка 745
Питання
Which term describes formation of new species?
Відповідь
speciation
Картка 746
Питання
What is reproductive isolation?
Відповідь
Barriers that prevent or greatly reduce gene flow between populations.
Картка 747
Питання
What is allopatric speciation?
Відповідь
Speciation after populations become geographically separated and diverge.
Картка 748
Питання
What is sympatric speciation?
Відповідь
Speciation without geographic separation, through reproductive isolation within the same area.
Картка 749
Питання
What are homologous structures?
Відповідь
Structures similar because they were inherited from a common ancestor, even if their functions differ.
Картка 750
Питання
Which term describes barriers reducing gene flow between populations?
Відповідь
reproductive isolation
Картка 751
Питання
Which term describes speciation following geographic separation?
Відповідь
allopatric speciation
Картка 752
Питання
Which term describes speciation within the same geographic area?
Відповідь
sympatric speciation
Картка 753
Питання
Which term describes structures similar through common ancestry?
Відповідь
homologous structures
Картка 754
Питання
What are analogous structures?
Відповідь
Structures with similar functions that evolved independently rather than from the same ancestral structure.
Картка 755
Питання
What is a common ancestor?
Відповідь
An ancestral population from which two or more descendant lineages evolved.
Картка 756
Питання
How does the fossil record provide evidence for evolution?
Відповідь
It documents organisms from different times, including appearance, change, persistence, and extinction of lineages.
Картка 757
Питання
How do DNA and protein sequences provide evidence of common ancestry?
Відповідь
Shared sequences are inherited; greater similarity generally indicates more recent common ancestry.
Картка 758
Питання
Which term describes functionally similar structures of independent evolutionary origin?
Відповідь
analogous structures
Картка 759
Питання
Which term describes an ancestral population shared by descendant lineages?
Відповідь
a common ancestor
Картка 760
Питання
What is the evolutionary significance of extinction?
Відповідь
It permanently ends a lineage and can alter ecological opportunities and the future diversification of survivors.
Картка 761
Питання
Do individual organisms evolve during their lifetimes?
Відповідь
No. Individuals develop and acclimate; evolution is heritable change in populations across generations.
Картка 762
Питання
Why is evolution represented as a branching tree rather than a ladder?
Відповідь
Lineages split from common ancestors; living species are not arranged as stages toward a single goal.
Картка 763
Питання
How can island species support evolutionary explanations?
Відповідь
Their similarities to nearby mainland ancestors and unique local adaptations fit divergence after colonization and isolation.
Картка 764
Питання
How can geographic isolation lead to reproductive isolation?
Відповідь
Separated populations accumulate different mutations and experience different selection and drift until interbreeding is reduced.
Картка 765
Питання
Why can continuing gene flow slow speciation?
Відповідь
Movement of alleles between populations counteracts genetic divergence.
Картка 766
Питання
Why can unrelated species evolve similar traits?
Відповідь
Similar environmental challenges can favor similar functional solutions through convergent evolution.
Картка 767
Питання
Which parts of evolution are random and which are nonrandom?
Відповідь
Mutation and many sampling effects are random with respect to need; natural selection nonrandomly favors variants that reproduce better in a given environment.
Картка 768
Питання
What is conservation biology?
Відповідь
The science and practice of protecting biodiversity, ecological processes, and evolutionary potential.
Картка 769
Питання
What is habitat fragmentation?
Відповідь
Division of continuous habitat into smaller, isolated patches.
Картка 770
Питання
What is an endangered species?
Відповідь
A species facing a high risk of extinction in the wild.
Картка 771
Питання
What is in situ conservation?
Відповідь
Protection of species in their natural habitats and ecological communities.
Картка 772
Питання
Which term describes the protection of biodiversity and ecological processes?
Відповідь
conservation biology
Картка 773
Питання
Which term describes division of habitat into isolated patches?
Відповідь
habitat fragmentation
Картка 774
Питання
Which term describes a species at high risk of extinction?
Відповідь
an endangered species
Картка 775
Питання
Which term describes conservation within natural habitat?
Відповідь
in situ conservation
Картка 776
Питання
What is ex situ conservation?
Відповідь
Protection of organisms or genetic material outside the natural habitat.
Картка 777
Питання
What is a population bottleneck?
Відповідь
A sharp population reduction that can remove genetic variation by chance.
Картка 778
Питання
What is a wildlife corridor?
Відповідь
Habitat connecting isolated patches to permit movement and gene flow.
Картка 779
Питання
What major human-driven processes threaten biodiversity?
Відповідь
Habitat loss, overexploitation, invasive species, pollution, and climate change.
Картка 780
Питання
Which term describes conservation outside natural habitat?
Відповідь
ex situ conservation
Картка 781
Питання
Which term describes a severe population reduction that loses genetic diversity?
Відповідь
a population bottleneck
Картка 782
Питання
Which term describes habitat linking isolated populations?
Відповідь
a wildlife corridor
Картка 783
Питання
What makes a protected area more effective than a boundary alone?
Відповідь
Adequate size, representative habitat, enforcement, connectivity, local support, and management of external threats.
Картка 784
Питання
Why is long-term population monitoring important in conservation?
Відповідь
It reveals trends, tests whether management works, and provides early warning of decline.
Картка 785
Питання
How can ecosystem services support the case for conservation?
Відповідь
Healthy ecosystems provide benefits such as pollination, water purification, carbon storage, soil formation, and cultural value.
Картка 786
Питання
Why are very small populations especially vulnerable to extinction?
Відповідь
Chance events, inbreeding, low genetic diversity, and difficulty finding mates can reinforce decline.
Картка 787
Питання
What are benefits and limits of captive-breeding programs?
Відповідь
They can prevent immediate extinction and manage breeding, but may lose diversity, alter behavior, and fail without safe habitat for release.
Картка 788
Питання
Why can controlling an invasive species aid conservation?
Відповідь
It can reduce predation, competition, disease, or habitat alteration affecting native species.
Картка 789
Питання
Why must conservation priorities consider more than species count?
Відповідь
Endemism, evolutionary distinctness, ecological roles, threat severity, feasibility, and human needs also matter.
Картка 790
Питання
What is an adaptation?
Відповідь
A heritable characteristic that increases reproductive success in a particular environment.
Картка 791
Питання
What is acclimation?
Відповідь
A reversible physiological or behavioral adjustment by an individual to environmental change.
Картка 792
Питання
What is a structural adaptation?
Відповідь
An inherited anatomical feature that improves performance in an environment.
Картка 793
Питання
What is a physiological adaptation?
Відповідь
An inherited functional or biochemical feature that improves performance in an environment.
Картка 794
Питання
Which term describes a heritable trait improving reproductive success in context?
Відповідь
an adaptation
Картка 795
Питання
Which term describes an individual's reversible adjustment to environmental change?
Відповідь
acclimation
Картка 796
Питання
Which term describes an adaptive anatomical feature?
Відповідь
a structural adaptation
Картка 797
Питання
Which term describes an adaptive functional or biochemical feature?
Відповідь
a physiological adaptation
Картка 798
Питання
What is a behavioral adaptation?
Відповідь
An inherited behavior pattern that improves survival or reproduction.
Картка 799
Питання
What is an environmental tolerance range?
Відповідь
The range of an abiotic condition within which an organism can survive and reproduce.
Картка 800
Питання
What is evolutionary fitness?
Відповідь
Relative contribution of an individual or genotype to future generations.
Картка 801
Питання
How can a thick cuticle and reduced leaves help a desert plant?
Відповідь
The cuticle lowers surface permeability, while smaller leaves reduce the area from which water can evaporate.
Картка 802
Питання
Which term describes an adaptive behavior pattern?
Відповідь
a behavioral adaptation
Картка 803
Питання
Which term describes the survivable range of an abiotic condition?
Відповідь
an environmental tolerance range
Картка 804
Питання
Which term describes relative reproductive contribution to future generations?
Відповідь
evolutionary fitness
Картка 805
Питання
How can a streamlined body adapt an aquatic animal to movement?
Відповідь
It reduces drag, lowering the energy needed to move through water.
Картка 806
Питання
Does an organism develop an adaptation because it needs one?
Відповідь
No. Heritable variants arise without regard to need, and selection changes their frequencies across generations.
Картка 807
Питання
Why may organisms from different thermal environments have enzymes with different temperature optima?
Відповідь
Selection favors protein structures that balance flexibility and stability under local temperatures.
Картка 808
Питання
Why is an adaptation rarely beneficial in every environment?
Відповідь
Traits carry costs and their advantage depends on local resources, competitors, predators, and physical conditions.
Картка 809
Питання
How does phenotypic plasticity differ from genetic adaptation?
Відповідь
Plasticity lets one genotype produce different phenotypes; adaptation is a heritable population trait shaped across generations.
Картка 810
Питання
What is local adaptation?
Відповідь
A population has higher fitness in its home environment than foreign populations because selection favored local traits.
Картка 811
Питання
What is an ecological niche?
Відповідь
The set of environmental conditions, resources, interactions, and functional roles associated with a species.
Картка 812
Питання
What is a habitat?
Відповідь
The physical place or environment where an organism lives.
Картка 813
Питання
What is a fundamental niche?
Відповідь
The full range of conditions and resources a species could use without limiting biotic interactions.
Картка 814
Питання
What is a realized niche?
Відповідь
The conditions and resources a species actually uses after competition and other interactions.
Картка 815
Питання
Which term describes a species' environmental requirements and ecological role?
Відповідь
an ecological niche
Картка 816
Питання
Which term describes the place where an organism lives?
Відповідь
a habitat
Картка 817
Питання
Which term describes the potential niche without limiting biotic interactions?
Відповідь
a fundamental niche
Картка 818
Питання
Which term describes the niche actually occupied in nature?
Відповідь
a realized niche
Картка 819
Питання
What is competition?
Відповідь
An interaction in which organisms reduce one another's access to a limited resource.
Картка 820
Питання
What is mutualism?
Відповідь
An interaction in which both participating species benefit.
Картка 821
Питання
What is predation?
Відповідь
An interaction in which one organism kills and consumes another.
Картка 822
Питання
How does a habitat differ from a niche?
Відповідь
A habitat is where an organism lives; a niche includes how it uses conditions and resources and interacts there.
Картка 823
Питання
Which term describes an interaction over a limited resource that harms both competitors?
Відповідь
competition
Картка 824
Питання
Which term describes an interspecific interaction benefiting both partners?
Відповідь
mutualism
Картка 825
Питання
Which term describes an interaction where one organism kills and eats another?
Відповідь
predation
Картка 826
Питання
What kinds of factors define a niche?
Відповідь
Abiotic factors such as temperature and moisture, plus biotic factors such as food, competitors, predators, and partners.
Картка 827
Питання
What does competitive exclusion predict?
Відповідь
Species with effectively identical niches cannot coexist indefinitely under stable conditions; one is excluded or niches diverge.
Картка 828
Питання
How can resource partitioning reduce competition?
Відповідь
Species use different resources, places, or times, reducing niche overlap.
Картка 829
Питання
What is a keystone species?
Відповідь
A species whose effect on community structure is disproportionately large relative to its abundance.
Картка 830
Питання
Why can an introduced species expand rapidly in a new community?
Відповідь
It may encounter abundant resources, suitable climate, and fewer predators, pathogens, or competitors.
Картка 831
Питання
Can an organism alter the niche conditions of other species?
Відповідь
Yes. Ecosystem engineers modify habitat structure or resource availability, changing opportunities for other organisms.
Картка 832
Питання
What is a population?
Відповідь
Individuals of the same species living in the same area at the same time.
Картка 833
Питання
What is an ecological community?
Відповідь
Populations of different species living and interacting in an area.
Картка 834
Питання
What is an ecosystem?
Відповідь
A community together with its physical environment and their interactions.
Картка 835
Питання
What is carrying capacity?
Відповідь
The population size an environment can sustain over time under given conditions.
Картка 836
Питання
Which term describes same-species individuals sharing an area and time?
Відповідь
a population
Картка 837
Питання
Which term describes interacting populations of different species?
Відповідь
an ecological community
Картка 838
Питання
Which term describes a community plus its abiotic environment?
Відповідь
an ecosystem
Картка 839
Питання
Which term describes the long-term supportable population size?
Відповідь
carrying capacity
Картка 840
Питання
What is population density?
Відповідь
The number of individuals per unit area or volume.
Картка 841
Питання
What is a limiting factor?
Відповідь
A resource or condition that restricts population growth or distribution.
Картка 842
Питання
What is a density-dependent factor?
Відповідь
A factor whose effect strengthens as population density increases.
Картка 843
Питання
What is a density-independent factor?
Відповідь
A factor whose effect is not primarily determined by population density.
Картка 844
Питання
Which term describes individuals per unit area or volume?
Відповідь
population density
Картка 845
Питання
Which term describes a resource or condition restricting a population?
Відповідь
a limiting factor
Картка 846
Питання
Which term describes a factor with stronger effects at higher density?
Відповідь
a density-dependent factor
Картка 847
Питання
Which term describes a factor acting largely regardless of population density?
Відповідь
a density-independent factor
Картка 848
Питання
What is exponential population growth?
Відповідь
Growth at a constant per-capita rate, producing a J-shaped curve under ideal conditions.
Картка 849
Питання
What is logistic population growth?
Відповідь
Growth that slows as population size approaches carrying capacity, producing an S-shaped model.
Картка 850
Питання
What four processes directly change population size?
Відповідь
Births and immigration increase it; deaths and emigration decrease it.
Картка 851
Питання
Under what conditions can exponential growth occur temporarily?
Відповідь
Resources are abundant and limiting effects such as competition, disease, and predation are weak.
Картка 852
Питання
Which term describes J-shaped growth at constant per-capita rate?
Відповідь
exponential population growth
Картка 853
Питання
Which term describes S-shaped growth that slows near carrying capacity?
Відповідь
logistic population growth
Картка 854
Питання
Why is infectious disease often density dependent?
Відповідь
Close or frequent contact at high density increases transmission opportunities.
Картка 855
Питання
Give an example of a density-independent population factor.
Відповідь
A severe storm, wildfire, drought, or freeze can affect populations regardless of their initial density.
Картка 856
Питання
When is quadrat sampling useful?
Відповідь
For estimating abundance or frequency of sessile or slow-moving organisms in defined areas.
Картка 857
Питання
What can a transect reveal?
Відповідь
How species occurrence or abundance changes along an environmental gradient.
Картка 858
Питання
What can happen when a population overshoots carrying capacity?
Відповідь
Resource depletion may raise mortality or lower reproduction, causing decline or oscillation.
Картка 859
Питання
What is the basic mark–recapture estimate of population size?
Відповідь
First sample marked × second sample total ÷ marked individuals recaptured.
Картка 860
Питання
What assumptions improve a mark–recapture estimate?
Відповідь
Marks persist and do not affect survival, marked individuals mix, capture probability is similar, and the population is effectively closed.
Картка 861
Питання
Why does a correlation between two population variables not prove causation?
Відповідь
A third factor, reverse influence, chance, or biased sampling could produce the association.
Картка 862
Питання
What is a trophic level?
Відповідь
A feeding position in a food chain or web.
Картка 863
Питання
What is a producer?
Відповідь
An autotroph that converts inorganic carbon into organic matter.
Картка 864
Питання
What is a consumer?
Відповідь
An organism obtaining energy and matter by eating other organisms or organic material.
Картка 865
Питання
What is a decomposer?
Відповідь
An organism that externally digests dead material and wastes and absorbs the products.
Картка 866
Питання
Which term describes a feeding position in an ecosystem?
Відповідь
a trophic level
Картка 867
Питання
Which term describes an autotroph forming organic matter?
Відповідь
a producer
Картка 868
Питання
Which term describes an organism feeding on other organic matter?
Відповідь
a consumer
Картка 869
Питання
Which term describes an organism digesting dead organic matter externally?
Відповідь
a decomposer
Картка 870
Питання
What is a food chain?
Відповідь
A linear representation of feeding and energy-transfer relationships.
Картка 871
Питання
What is a food web?
Відповідь
A network of interconnected feeding relationships in a community.
Картка 872
Питання
What is gross primary productivity?
Відповідь
The total rate at which producers capture energy into organic matter.
Картка 873
Питання
What is net primary productivity?
Відповідь
Producer energy stored as new biomass after subtracting producer respiration from gross primary productivity.
Картка 874
Питання
Which term describes a linear feeding sequence?
Відповідь
a food chain
Картка 875
Питання
Which term describes a network of connected food chains?
Відповідь
a food web
Картка 876
Питання
Which term describes the total producer energy-capture rate?
Відповідь
gross primary productivity
Картка 877
Питання
Which term describes producer biomass gain after respiration?
Відповідь
net primary productivity
Картка 878
Питання
What is ecological productivity?
Відповідь
The rate of biomass or energy production per unit area or volume.
Картка 879
Питання
What is a biogeochemical cycle?
Відповідь
Movement of an element or compound through organisms and the physical environment.
Картка 880
Питання
Why is less energy available at each higher trophic level?
Відповідь
Not all biomass is eaten or digested, and organisms use energy in respiration, movement, maintenance, and heat loss.
Картка 881
Питання
Why does energy flow rather than cycle through an ecosystem?
Відповідь
Energy enters mainly as light and ultimately disperses as heat, which ecosystems cannot fully recycle.
Картка 882
Питання
Which term describes the rate of biomass or energy production?
Відповідь
ecological productivity
Картка 883
Питання
Which term describes cycling of matter through living and nonliving reservoirs?
Відповідь
a biogeochemical cycle
Картка 884
Питання
Why can matter cycle through an ecosystem?
Відповідь
Atoms are conserved and repeatedly transferred among organisms, detritus, soil, water, and atmosphere.
Картка 885
Питання
Why is a pyramid of energy always upright?
Відповідь
Usable energy decreases between trophic levels because every transfer includes losses.
Картка 886
Питання
How are gross and net primary productivity related?
Відповідь
NPP = GPP − producer respiration.
Картка 887
Питання
How do decomposers support nutrient cycling?
Відповідь
They break down dead material and wastes, releasing inorganic nutrients for reuse.
Картка 888
Питання
What processes move carbon rapidly between organisms and the atmosphere?
Відповідь
Photosynthesis removes carbon dioxide; respiration, decomposition, and combustion release it.
Картка 889
Питання
Why is nitrogen fixation important?
Відповідь
It converts atmospheric nitrogen gas into forms that can enter biological nitrogen metabolism.
Картка 890
Питання
How can excess nitrogen or phosphorus cause eutrophication?
Відповідь
Nutrient enrichment drives algal growth; decomposition of the biomass consumes oxygen and can create hypoxic water.
Картка 891
Питання
Why can a persistent pollutant reach higher concentrations at higher trophic levels?
Відповідь
Predators consume contaminant stored in many prey, and the substance is not readily broken down or excreted.
Картка 892
Питання
How is trophic-transfer efficiency calculated?
Відповідь
Energy or biomass gained by the higher trophic level ÷ energy or biomass available at the lower level × 100%.
Картка 893
Питання
What is phenotypic variation?
Відповідь
Differences in observable traits among individuals of a population.
Картка 894
Питання
What is heritable variation?
Відповідь
Trait differences that can be transmitted genetically to offspring.
Картка 895
Питання
What is a selection pressure?
Відповідь
An environmental factor causing differences in survival or reproduction among phenotypes.
Картка 896
Питання
What is relative fitness?
Відповідь
An individual's reproductive success compared with others in the population.
Картка 897
Питання
Which term describes observable differences among individuals?
Відповідь
phenotypic variation
Картка 898
Питання
Which term describes genetically transmissible trait differences?
Відповідь
heritable variation
Картка 899
Питання
Which term describes an environmental factor producing differential reproductive success?
Відповідь
a selection pressure
Картка 900
Питання
Which term describes reproductive success relative to other individuals?
Відповідь
relative fitness
Картка 901
Питання
What is directional selection?
Відповідь
Selection favoring one extreme phenotype and shifting a population's trait distribution.
Картка 902
Питання
What is stabilizing selection?
Відповідь
Selection favoring intermediate phenotypes and acting against extremes.
Картка 903
Питання
What is disruptive selection?
Відповідь
Selection favoring both extreme phenotypes over intermediates.
Картка 904
Питання
What is sexual selection?
Відповідь
Selection arising from differences in mating success.
Картка 905
Питання
Which term describes selection shifting a trait toward one extreme?
Відповідь
directional selection
Картка 906
Питання
Which term describes selection favoring intermediate phenotypes?
Відповідь
stabilizing selection
Картка 907
Питання
Which term describes selection favoring both trait extremes?
Відповідь
disruptive selection
Картка 908
Питання
Which term describes selection caused by unequal mating success?
Відповідь
sexual selection
Картка 909
Питання
What conditions are required for natural selection?
Відповідь
Individuals vary, some variation is heritable, more offspring are produced than can reproduce, and variants differ in reproductive success.
Картка 910
Питання
How does natural selection produce antibiotic-resistant bacterial populations?
Відповідь
Existing resistant variants survive treatment and reproduce more than susceptible bacteria.
Картка 911
Питання
Does an antibiotic cause bacteria to mutate specifically toward resistance?
Відповідь
No. Resistance variants arise without regard to need; treatment selects among them.
Картка 912
Питання
Can an individual become genetically adapted through natural selection?
Відповідь
No. Selection acts on individuals, but adaptation is a population change across generations.
Картка 913
Питання
How does artificial selection differ from natural selection?
Відповідь
Humans choose breeding traits in artificial selection; environmental conditions determine differential reproduction in natural selection.
Картка 914
Питання
How does natural selection change a population?
Відповідь
Individuals with advantageous heritable variants leave more offspring, increasing those alleles over generations.
Картка 915
Питання
Why is fitness environment-dependent?
Відповідь
A trait that improves reproduction in one environment may be neutral or costly in another.
Картка 916
Питання
How does genetic drift differ from natural selection?
Відповідь
Drift changes allele frequencies by chance sampling; selection changes them through consistent fitness differences.
Картка 917
Питання
What is ecosystem stability?
Відповідь
The capacity of an ecosystem to maintain or recover its structure and functions despite disturbance.
Картка 918
Питання
What is an ecological tipping point?
Відповідь
A threshold beyond which feedbacks can drive a large and difficult-to-reverse ecosystem shift.
Картка 919
Питання
What is a mesocosm?
Відповідь
A controlled, simplified ecosystem used to investigate ecological processes under more realistic conditions than a small laboratory vessel.
Картка 920
Питання
What is a sustainable yield?
Відповідь
A harvest rate that can continue without causing long-term resource decline under prevailing conditions.
Картка 921
Питання
Which term describes the capacity of an ecosystem to persist or recover after disturbance?
Відповідь
ecosystem stability
Картка 922
Питання
Which term describes a threshold triggering a major hard-to-reverse ecosystem shift?
Відповідь
an ecological tipping point
Картка 923
Питання
Which term describes a controlled model ecosystem used for experiments?
Відповідь
a mesocosm
Картка 924
Питання
Which term describes a harvest rate that avoids long-term depletion?
Відповідь
a sustainable yield
Картка 925
Питання
What is eutrophication?
Відповідь
Nutrient enrichment of water that stimulates excess primary production and can lead to oxygen depletion.
Картка 926
Питання
What is biomagnification?
Відповідь
Increase in concentration of a persistent pollutant at successively higher trophic levels.
Картка 927
Питання
What is rewilding?
Відповідь
Ecosystem restoration that rebuilds natural processes, species interactions, and self-sustaining ecological function.
Картка 928
Питання
What features can make an ecosystem more stable?
Відповідь
Diverse functional roles, connected habitats, intact food webs, nutrient cycling, and balancing feedbacks can help the system resist or recover from disturbance.
Картка 929
Питання
Which term describes nutrient enrichment that can deplete oxygen in water?
Відповідь
eutrophication
Картка 930
Питання
Which term describes increasing pollutant concentration up a food chain?
Відповідь
biomagnification
Картка 931
Питання
Which term describes restoration focused on natural processes and self-sustaining ecosystems?
Відповідь
rewilding
Картка 932
Питання
How could extensive Amazon deforestation push the ecosystem toward a tipping point?
Відповідь
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.
Картка 933
Питання
What are a benefit and a limitation of using a mesocosm?
Відповідь
It allows controlled experiments with interacting organisms, but its simplified scale cannot reproduce every process or long-term influence in a natural ecosystem.
Картка 934
Питання
Why should a fishery harvest below an uncertain maximum sustainable yield?
Відповідь
Population estimates and recruitment vary, so a safety margin reduces the chance that error or a poor breeding year drives long-term decline.
Картка 935
Питання
How can intensive agriculture reduce ecosystem stability?
Відповідь
Habitat loss, low crop diversity, soil degradation, heavy water use, pesticides, and nutrient runoff can weaken food webs and ecosystem processes.
Картка 936
Питання
Why can microplastic pollution harm aquatic ecosystems?
Відповідь
Small persistent particles can be ingested, carry additives or other pollutants, damage feeding and tissues, and move through food webs.
Картка 937
Питання
How can rewilding improve ecosystem stability?
Відповідь
Restoring native species, habitat connections, and natural disturbance or grazing processes can rebuild feedbacks and allow the ecosystem to maintain itself with less intervention.
Картка 938
Питання
What is the greenhouse effect?
Відповідь
Warming caused when atmospheric gases absorb and re-emit outgoing infrared radiation.
Картка 939
Питання
What is a greenhouse gas?
Відповідь
An atmospheric gas that absorbs infrared radiation at wavelengths emitted by Earth.
Картка 940
Питання
What is carbon dioxide (CO₂)?
Відповідь
A long-lived greenhouse gas increased mainly by fossil-fuel combustion, cement production, and land-use change.
Картка 941
Питання
What is methane (CH₄)?
Відповідь
A potent greenhouse gas emitted by sources including fossil-fuel systems, livestock, rice cultivation, wetlands, and waste.
Картка 942
Питання
Which term describes warming from absorption and re-emission of infrared radiation?
Відповідь
the greenhouse effect
Картка 943
Питання
Which term describes an atmospheric infrared-absorbing gas?
Відповідь
a greenhouse gas
Картка 944
Питання
Which term describes the long-lived greenhouse gas strongly increased by fossil fuels?
Відповідь
carbon dioxide (CO₂)
Картка 945
Питання
Which term describes the potent short-lived greenhouse gas from biological and fossil sources?
Відповідь
methane (CH₄)
Картка 946
Питання
What is albedo?
Відповідь
The fraction of incoming radiation reflected by a surface.
Картка 947
Питання
What is a carbon sink?
Відповідь
A reservoir that absorbs more carbon than it releases over a specified period.
Картка 948
Питання
What is ocean acidification?
Відповідь
Decline in seawater pH caused mainly by absorption of human-emitted carbon dioxide.
Картка 949
Питання
What is climate change?
Відповідь
A persistent change in the statistical patterns of climate over decades or longer.
Картка 950
Питання
Which term describes surface reflectivity?
Відповідь
albedo
Картка 951
Питання
Which term describes a reservoir with net carbon uptake?
Відповідь
a carbon sink
Картка 952
Питання
Which term describes seawater pH decline from absorbed carbon dioxide?
Відповідь
ocean acidification
Картка 953
Питання
Which term describes long-term change in climate patterns?
Відповідь
climate change
Картка 954
Питання
What is the enhanced greenhouse effect?
Відповідь
Additional warming caused by human-driven increases in greenhouse-gas concentrations.
Картка 955
Питання
How do climate mitigation and climate adaptation differ?
Відповідь
Mitigation limits the magnitude of climate change; adaptation reduces harm from changes that occur.
Картка 956
Питання
How does increasing greenhouse-gas concentration alter Earth's energy balance?
Відповідь
Less outgoing infrared energy initially escapes to space, so the climate warms until energy balance is restored at a higher temperature.
Картка 957
Питання
How can melting ice amplify warming?
Відповідь
Less bright ice lowers albedo, so darker land or water absorbs more solar energy and causes further warming.
Картка 958
Питання
How can climate change alter species distributions?
Відповідь
Temperature, rainfall, seasons, sea level, and interactions shift, moving or shrinking areas with suitable conditions.
Картка 959
Питання
Why can ocean acidification harm calcifying organisms?
Відповідь
Carbonate chemistry changes, reducing availability of carbonate ions used to build calcium-carbonate structures.
Картка 960
Питання
How can ecosystem protection contribute to climate mitigation?
Відповідь
Protecting forests, wetlands, soils, and coastal habitats can avoid emissions and maintain or increase carbon storage.
960 карток
IB Biology SL Flashcards: Complete Course Review
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