AP Biology Flashcards: Complete 8-Unit Course Review
Review all 8 AP Biology units with original flashcards for concepts, pathways, experimental design, data interpretation, and FRQ reasoning.
このデッキについて
AP Biology Flashcards: Complete 8-Unit Course Review
The current AP Biology framework covers eight units, from chemistry of life through ecology. This 540-card deck turns that full course into short, original retrieval prompts, with science-practice reasoning mixed into the biology instead of parked in a separate section.
What the cards practice
The cards connect terms to functions, structures to consequences, pathway steps to inputs, outputs, locations, and regulation, and evidence to biological claims. Separate prompts cover useful reverse mappings when they are real study tasks—for example, identifying a process from its location or choosing the inference supported by a result. Short original scenarios also practice describing patterns, explaining mechanisms, predicting changes, justifying claims, setting up calculations, and evaluating evidence.
The deck does not mechanically reverse every definition or pathway. It leaves out copied exam material, scoring language, official figures, exhaustive protocols, broad essay prompts, textbook-specific trivia, and advanced-college details outside the current course boundary.
Learning order
The sequence follows Units 1–8. Within each unit it moves from prerequisites to processes, applications, experiments, data, and FRQ-style reasoning, while spacing close variants apart. Long-term spacing and interleaving are left to the review scheduler.
What still needs practice
Flashcards are useful for recall and small reasoning moves, but they cannot replace laboratory work, graph construction, extended data analysis, or timed multiple-choice and free-response practice. Use the deck beside class labs and full original practice questions.
Scope and provenance
The course boundary was reviewed on September 1, 2026 against the College Board AP Biology course page, the Fall 2025 Course and Exam Description, its current clarifications and corrections, the 2026–27 course-change table, and the current exam page. The selection, prompts, answers, examples, sequence, metadata, and cover are independently created from common biological knowledge and source checks. No exam questions, scoring guidelines, CED text, answer keys, or official figures were copied or transformed.
The Common knowledge · CC0 1.0 label applies to the original wording, organization, metadata, and generated media to the extent applicable rights exist. It does not claim ownership of biological facts, AP or College Board names, or third-party source material.
This independent, unofficial study deck is not affiliated with, endorsed by, or sponsored by College Board. AP and College Board names identify the course and exam only. Official requirements: https://apcentral.collegeboard.org/courses/ap-biology
このデッキのカード
カード 1
質問
Why is a water molecule polar?
回答
Oxygen pulls shared electrons more strongly than hydrogen, giving oxygen a partial negative charge and the hydrogens partial positive charges.
カード 2
質問
Which elements make up most biological molecules?
回答
Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur—often shortened to CHNOPS.
カード 3
質問
What is the relationship between a monomer and a polymer?
回答
Monomers are small building blocks; polymers are chains or networks made from repeated monomers.
カード 4
質問
What is a monosaccharide's main role in cells?
回答
It can provide quick energy and serve as a building block for larger carbohydrates.
カード 5
質問
Why do lipids mix poorly with water?
回答
Most of their bonds are nonpolar, so water cannot form favorable interactions with them.
カード 6
質問
What three parts make up a nucleotide?
回答
A five-carbon sugar, a phosphate group, and a nitrogenous base.
カード 7
質問
What parts of an amino acid vary and stay constant?
回答
The amino group, carboxyl group, hydrogen, and central carbon are shared; the side chain, or R group, varies.
カード 8
質問
What does pH measure?
回答
The negative logarithm of hydrogen-ion concentration; lower pH means more hydrogen ions.
カード 9
質問
What is a hydrogen bond in liquid water?
回答
A weak attraction between a partially positive hydrogen on one water molecule and a partially negative oxygen on another.
カード 10
質問
How does an unsaturated fatty acid differ from a saturated one?
回答
An unsaturated fatty acid has at least one carbon–carbon double bond; a saturated fatty acid has none.
カード 11
質問
What bond links amino acids in a polypeptide?
回答
A peptide bond.
カード 12
質問
What does dehydration synthesis do?
回答
It joins subunits with a covalent bond while removing the elements of water.
カード 13
質問
How does cohesion help water move through a plant?
回答
Hydrogen bonds keep water molecules linked, helping a continuous column rise through xylem.
カード 14
質問
How do plants and animals differ in short-term glucose storage?
回答
Plants store glucose mainly as starch; animals store it mainly as glycogen.
カード 15
質問
What determines a protein's primary structure?
回答
Its amino-acid sequence.
カード 16
質問
How does a cis double bond affect a fatty-acid tail?
回答
It introduces a bend that prevents neighboring tails from packing tightly.
カード 17
質問
How does adhesion support water transport in narrow tubes?
回答
Water sticks to polar surfaces, helping it resist gravity along cell walls.
カード 18
質問
Which base pairing distinguishes RNA from DNA?
回答
RNA uses uracil, so adenine pairs with uracil instead of thymine.
カード 19
質問
What stabilizes common protein secondary structures?
回答
Hydrogen bonds between atoms in the polypeptide backbone.
カード 20
質問
Why can carbon form so many biological structures?
回答
It has four valence electrons and can form four stable covalent bonds, including chains, branches, and rings.
カード 21
質問
Why can some insects stand on water?
回答
Cohesion among surface water molecules creates high surface tension.
カード 22
質問
What does hydrolysis do to a biological polymer?
回答
It adds the elements of water to break a covalent bond between subunits.
カード 23
質問
What carbohydrate strengthens plant cell walls?
回答
Cellulose.
カード 24
質問
Why are fats useful for long-term energy storage?
回答
Their many C–H bonds store substantial chemical energy, and hydrophobic storage adds little water mass.
カード 25
質問
How does water buffer rapid temperature change?
回答
Breaking and forming many hydrogen bonds absorbs or releases substantial heat, giving water a high specific heat.
カード 26
質問
What does antiparallel mean for a DNA double helix?
回答
Its two strands run in opposite directions: one 5′→3′ and the other 3′→5′.
カード 27
質問
What mainly drives a protein's tertiary structure?
回答
Interactions among side chains, including hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bridges.
カード 28
質問
What is a trace element?
回答
An element an organism needs in very small amounts, such as iron in many electron-transfer proteins.
カード 29
質問
Why does sweating cool an organism?
回答
The fastest water molecules escape as vapor, carrying heat away from the surface.
カード 30
質問
A cell builds a polysaccharide from sugars. Is water consumed or released?
回答
Released. Forming each linkage by dehydration removes water.
カード 31
質問
Why can branching help a storage polysaccharide release glucose quickly?
回答
More branch ends give enzymes more sites to work at once.
カード 32
質問
What makes a phospholipid amphipathic?
回答
It has a polar, hydrophilic head and nonpolar, hydrophobic tails.
カード 33
質問
Where is biological information encoded in a nucleic acid?
回答
In the linear sequence of nucleotide bases.
カード 34
質問
What is quaternary protein structure?
回答
The arrangement of two or more polypeptide subunits into one functional protein.
カード 35
質問
Why does ice float on liquid water?
回答
Stable hydrogen bonds hold ice molecules in an open lattice, making ice less dense than liquid water.
カード 36
質問
How does electronegativity affect a covalent bond?
回答
A difference in attraction for electrons makes electron sharing unequal and can create a polar bond.
カード 37
質問
A digestive reaction adds water while splitting a macromolecule. What reaction is this?
回答
Hydrolysis.
カード 38
質問
What links monosaccharides in a polysaccharide?
回答
Glycosidic covalent bonds.
カード 39
質問
Why do phospholipids form bilayers in water?
回答
Hydrophilic heads face water while hydrophobic tails cluster away from it.
カード 40
質問
To which end are nucleotides added during nucleic-acid synthesis?
回答
The 3′ end of the growing strand.
カード 41
質問
Why can one amino-acid substitution change protein function?
回答
It can alter side-chain interactions, folding, stability, or an active or binding site.
カード 42
質問
How does a buffer resist a pH change?
回答
It can accept added hydrogen ions or donate them when hydrogen-ion concentration falls.
カード 43
質問
Why is water a useful solvent for cells?
回答
Its partial charges surround ions and other polar molecules, separating and dispersing them.
カード 44
質問
Why do functional groups matter in organic molecules?
回答
They give carbon skeletons predictable chemical properties, such as polarity, acidity, or reactivity.
カード 45
質問
Why can two polymers built from similar monomers have different functions?
回答
Their monomer sequence, branching, length, and three-dimensional shape can differ.
カード 46
質問
A seedling consumes stored starch. What happens to the starch?
回答
Hydrolysis breaks it into smaller sugars that can enter energy pathways.
カード 47
質問
What are two biological roles of steroids?
回答
Some act as signaling molecules, and cholesterol helps stabilize animal cell membranes.
カード 48
質問
What bond forms the backbone of a nucleic-acid strand?
回答
Covalent phosphodiester bonds link the sugar of one nucleotide to the phosphate of the next.
カード 49
質問
What does denaturation do to a protein?
回答
It disrupts the protein's three-dimensional shape and often its function without usually breaking the primary peptide chain.
カード 50
質問
An enzyme works best near pH 7 but slows at pH 3. What is a likely explanation?
回答
Extra hydrogen ions changed charges and interactions that maintain the enzyme's active shape.
カード 51
質問
What structure encloses every cell?
回答
A plasma membrane.
カード 52
質問
What is the nucleus's main function?
回答
It houses most eukaryotic DNA and is a major site of DNA replication and transcription.
カード 53
質問
Why does surface-area-to-volume ratio fall as a cell grows?
回答
Volume increases with the cube of length, while surface area increases with the square.
カード 54
質問
What does the fluid mosaic model describe?
回答
A dynamic phospholipid bilayer containing mobile proteins, sterols, and carbohydrates.
カード 55
質問
What drives simple diffusion?
回答
Random molecular motion produces net movement from higher to lower concentration.
カード 56
質問
How does active transport differ from facilitated diffusion?
回答
Active transport moves a substance against its gradient using energy; facilitated diffusion moves it down a gradient.
カード 57
質問
Why does compartmentalization increase cellular efficiency?
回答
It concentrates enzymes and substrates and maintains distinct conditions for different reactions.
カード 58
質問
When should a light microscope be preferred over an electron microscope?
回答
When observing living cells or dynamic processes at lower resolution.
カード 59
質問
What does the nucleolus produce?
回答
Ribosomal RNA and early ribosome subunits.
カード 60
質問
Does passive transport require direct cellular energy?
回答
No. It moves substances down an electrochemical or concentration gradient.
カード 61
質問
What feature separates prokaryotic from eukaryotic cells?
回答
Eukaryotic cells have a membrane-bound nucleus and other membrane-bound organelles; prokaryotic cells do not.
カード 62
質問
Which membrane region blocks most ions and polar molecules?
回答
The hydrophobic interior formed by phospholipid tails.
カード 63
質問
What happens on rough endoplasmic reticulum?
回答
Bound ribosomes make proteins for secretion, membranes, or the endomembrane system.
カード 64
質問
How does facilitated diffusion differ from simple diffusion?
回答
It uses a channel or carrier protein but still moves a substance down its gradient.
カード 65
質問
Where is prokaryotic DNA usually located?
回答
In a nucleoid region rather than inside a membrane-bound nucleus.
カード 66
質問
How does cholesterol affect an animal membrane?
回答
It buffers fluidity, limiting excess movement when warm and preventing tight packing when cool.
カード 67
質問
What does smooth endoplasmic reticulum do?
回答
It synthesizes lipids, detoxifies some compounds, and stores calcium in specialized cells.
カード 68
質問
What determines a channel protein's selectivity?
回答
Its pore size, shape, charge, and gating behavior.
カード 69
質問
What does the sodium–potassium pump accomplish?
回答
Using ATP, it exports three sodium ions and imports two potassium ions per cycle.
カード 70
質問
What do ribosomes do in both prokaryotic and eukaryotic cells?
回答
They translate mRNA into polypeptides.
カード 71
質問
What is the Golgi apparatus's role?
回答
It modifies, sorts, and packages proteins and lipids arriving from the endoplasmic reticulum.
カード 72
質問
What is osmosis?
回答
Net movement of water across a selectively permeable membrane toward lower free-water concentration.
カード 73
質問
Why does a high surface-area-to-volume ratio help a cell?
回答
It provides more membrane area per unit of cytoplasm for exchange with the environment.
カード 74
質問
How do unsaturated phospholipid tails affect membrane fluidity?
回答
Their bends reduce tight packing, usually increasing fluidity.
カード 75
質問
Trace a secreted protein after translation begins.
回答
Rough ER → transport vesicle → Golgi → secretory vesicle → plasma membrane.
カード 76
質問
What happens to an animal cell in a hypotonic solution?
回答
Water enters; the cell swells and may lyse.
カード 77
質問
What is cotransport?
回答
The downhill movement of one substance powers the uphill transport of another through the same protein.
カード 78
質問
What is the main role of a cell wall?
回答
It provides structural support and helps prevent excessive expansion.
カード 79
質問
What do lysosomes do?
回答
Their hydrolytic enzymes digest macromolecules and recycle damaged cell parts in an acidic compartment.
カード 80
質問
What happens to an animal cell in a hypertonic solution?
回答
Water leaves; the cell shrinks.
カード 81
質問
How do intestinal microvilli improve absorption?
回答
They increase membrane surface area without greatly increasing cell volume.
カード 82
質問
What can an integral membrane protein do?
回答
It can transport substances, receive signals, catalyze reactions, or anchor cell structures.
カード 83
質問
What is a central vacuole's major role in a plant cell?
回答
It stores solutes and water and helps maintain turgor pressure.
カード 84
質問
What happens to a plant cell in a hypotonic solution?
回答
Water enters and turgor pressure rises; the cell wall helps prevent bursting.
カード 85
質問
How can a proton gradient power sucrose uptake in a plant cell?
回答
Protons flow down their gradient through a symporter that carries sucrose uphill.
カード 86
質問
What evidence supports the endosymbiotic origin of mitochondria?
回答
They have double membranes, circular DNA, bacterial-like ribosomes, and divide independently by a similar process.
カード 87
質問
Which overall energy-conversion pathway mainly occurs in mitochondria?
回答
Most stages of aerobic cellular respiration and ATP production.
カード 88
質問
What happens to a plant cell in a hypertonic solution?
回答
Water leaves, turgor falls, and the membrane may pull from the wall during plasmolysis.
カード 89
質問
Why can't a standard light microscope resolve a ribosome clearly?
回答
A ribosome is smaller than the microscope's diffraction-limited resolution.
カード 90
質問
How do bacterial and plant cell walls differ?
回答
Bacterial walls usually contain peptidoglycan; plant walls contain cellulose.
カード 91
質問
Which overall energy-conversion pathway occurs in chloroplasts?
回答
Photosynthesis: converting light energy into chemical energy and fixing carbon.
カード 92
質問
A cubical cell doubles each side length. How do surface area and volume change?
回答
Surface area increases 4-fold; volume increases 8-fold.
カード 93
質問
What is the role of membrane carbohydrates?
回答
They help cells recognize and interact with one another.
カード 94
質問
What is water potential?
回答
A measure predicting water movement; water moves from higher to lower water potential.
カード 95
質問
How do microtubules support a cell?
回答
They resist compression, form tracks for motors, and build structures such as spindles, cilia, and flagella.
カード 96
質問
What is endocytosis?
回答
The plasma membrane folds inward to bring material into the cell in a vesicle.
カード 97
質問
What evidence supports the endosymbiotic origin of chloroplasts?
回答
They share bacterial-like DNA, ribosomes, division, and a double membrane consistent with engulfment.
カード 98
質問
In a membrane-permeability test, what is the independent variable?
回答
The factor deliberately changed, such as temperature or solute identity.
カード 99
質問
How do microfilaments support cell movement?
回答
Actin filaments interact with motor proteins to change cell shape, contract, and move materials.
カード 100
質問
What does the cytosol contain?
回答
Water, ions, small molecules, and proteins where many metabolic reactions occur.
カード 101
質問
Why can diffusion limit cell size?
回答
As dimensions grow, molecules must travel farther, while exchange area does not keep pace with metabolic volume.
カード 102
質問
What does selective permeability mean?
回答
The membrane allows some substances to cross more readily than others.
カード 103
質問
What is an intermediate filament's general role?
回答
It provides durable mechanical strength and helps anchor structures.
カード 104
質問
How does adding a nonpenetrating solute affect water potential?
回答
It makes solute potential, and usually total water potential, more negative.
カード 105
質問
What is exocytosis?
回答
A vesicle fuses with the plasma membrane and releases contents outside the cell.
カード 106
質問
Why can lysosomal enzymes digest safely inside a cell?
回答
A membrane isolates the acidic enzymes from most cytosolic components.
カード 107
質問
Why include an untreated membrane sample in an experiment?
回答
It provides a control baseline for judging the treatment's effect.
カード 108
質問
Why doesn't cell size alone identify whether a cell is prokaryotic?
回答
Sizes overlap; the presence or absence of internal membrane-bound structures is stronger evidence.
カード 109
質問
Why are organelle interactions important?
回答
Cell functions often require products to move through several specialized compartments rather than one organelle working alone.
カード 110
質問
What graph would show a size constraint clearly?
回答
Plot cell size on the x-axis and surface-area-to-volume ratio on the y-axis; the ratio should decline as size rises.
カード 111
質問
Which molecules cross a phospholipid bilayer most easily without proteins?
回答
Small nonpolar molecules, such as oxygen and carbon dioxide.
カード 112
質問
Two solutions have equal water potential. What is the net water movement?
回答
None, although water molecules still move both ways.
カード 113
質問
Why is ATP loss likely to disrupt ion balance?
回答
ATP-powered pumps stop maintaining gradients, so passive leaks move ions toward equilibrium.
カード 114
質問
How does folding an internal membrane help an organelle?
回答
It increases surface area for membrane-bound reactions without a matching increase in volume.
カード 115
質問
A dye leaves heated cells faster than unheated cells. What conclusion is supported?
回答
Heating increased membrane permeability under the tested conditions; the data alone do not identify the exact molecular damage.
カード 116
質問
What does an enzyme change in a reaction?
回答
It lowers activation energy, increasing reaction rate without changing the reaction's overall free-energy change.
カード 117
質問
What makes a reaction exergonic?
回答
It releases free energy and has a negative change in free energy under the stated conditions.
カード 118
質問
What are the overall inputs and outputs of photosynthesis?
回答
Carbon dioxide and water use light energy to produce carbohydrate and oxygen.
カード 119
質問
What are the overall reactants and products of aerobic cellular respiration?
回答
Organic fuel and oxygen are converted mainly to carbon dioxide, water, and ATP, with heat released.
カード 120
質問
How should reaction rate be calculated from product data?
回答
Divide the change in product amount by the elapsed time.
カード 121
質問
What makes an enzyme substrate-specific?
回答
The active site's shape and chemical properties favor particular substrates.
カード 122
質問
Where do the light reactions occur?
回答
In the thylakoid membranes of chloroplasts.
カード 123
質問
Where does glycolysis occur?
回答
In the cytosol.
カード 124
質問
What makes a reaction endergonic?
回答
It requires a net input of free energy and has a positive change in free energy.
カード 125
質問
What is induced fit?
回答
Substrate binding shifts the enzyme's shape into a form that better supports catalysis.
カード 126
質問
Where does the Calvin cycle occur?
回答
In the chloroplast stroma.
カード 127
質問
What does glycolysis produce per glucose?
回答
Two pyruvate, a net two ATP, and two NADH.
カード 128
質問
How can cells drive an endergonic reaction?
回答
They couple it to a sufficiently exergonic reaction so the combined free-energy change is negative.
カード 129
質問
Why isn't an enzyme consumed by the reaction it catalyzes?
回答
It returns to a reusable form after products leave the active site.
カード 130
質問
What do photosynthetic pigments do?
回答
They absorb particular wavelengths and transfer excitation energy into the light reactions.
カード 131
質問
Does glycolysis require oxygen directly?
回答
No. It can run without oxygen if NAD⁺ is regenerated.
カード 132
質問
What does ATP hydrolysis commonly provide?
回答
Usable free energy and a phosphate group that can change a molecule's reactivity or protein shape.
カード 133
質問
How does substrate concentration affect rate at low concentrations?
回答
Rate usually rises because more substrate molecules collide with available active sites.
カード 134
質問
Why do chlorophyll-containing leaves reflect green light?
回答
Chlorophyll absorbs green wavelengths less strongly than red and blue wavelengths.
カード 135
質問
Where does pyruvate oxidation occur in a eukaryotic cell?
回答
In the mitochondrial matrix.
カード 136
質問
Why is ATP called an energy-coupling molecule?
回答
Its hydrolysis links energy-releasing processes to cellular work.
カード 137
質問
Why does enzyme rate plateau at high substrate concentration?
回答
Most active sites are occupied, so enzyme amount becomes limiting.
カード 138
質問
What is photolysis of water?
回答
Light-driven splitting of water that supplies electrons and protons and releases oxygen.
カード 139
質問
What happens during pyruvate oxidation?
回答
Each pyruvate becomes acetyl-CoA, releasing carbon dioxide and reducing NAD⁺ to NADH.
カード 140
質問
Why measure an initial enzyme rate?
回答
Substrate depletion and product buildup have had less time to distort the rate.
カード 141
質問
How can high temperature reduce enzyme activity?
回答
Heat can disrupt interactions that maintain the enzyme's functional shape.
カード 142
質問
What is photosystem II's key contribution?
回答
It excites electrons and replaces them by oxidizing water.
カード 143
質問
Where does the citric acid cycle occur in eukaryotes?
回答
In the mitochondrial matrix.
カード 144
質問
What is oxidation?
回答
Loss of electrons, often accompanied by loss of hydrogen or gain of oxygen.
カード 145
質問
Why does each enzyme have an optimal pH range?
回答
pH changes charges on amino-acid side chains and can alter binding or folding.
カード 146
質問
What does the photosynthetic electron transport chain build?
回答
A proton gradient across the thylakoid membrane.
カード 147
質問
What is the citric acid cycle's main energy role?
回答
It oxidizes acetyl groups and transfers electrons to NADH and FADH₂, making a small amount of ATP.
カード 148
質問
In a photosynthesis experiment, why keep leaf area constant?
回答
Leaf area affects light capture and gas exchange, so changing it could confound the tested factor.
カード 149
質問
How does a competitive inhibitor reduce enzyme activity?
回答
It competes with substrate for the active site.
カード 150
質問
How does chloroplast ATP synthase make ATP?
回答
Protons flow from the thylakoid space to the stroma through ATP synthase, driving phosphorylation of ADP.
カード 151
質問
Where is the respiratory electron transport chain located in eukaryotes?
回答
In the inner mitochondrial membrane.
カード 152
質問
What is reduction?
回答
Gain of electrons, often accompanied by gain of hydrogen or loss of oxygen.
カード 153
質問
How can extra substrate weaken competitive inhibition?
回答
More substrate increases the chance that substrate, rather than inhibitor, occupies the active site.
カード 154
質問
What is photosystem I's key contribution?
回答
It re-energizes electrons used to reduce NADP⁺ to NADPH.
カード 155
質問
What is oxygen's role in aerobic respiration?
回答
It is the final electron acceptor and combines with electrons and protons to form water.
カード 156
質問
A respiration graph gets steeper after temperature rises. What does the slope show?
回答
A higher rate of the measured respiratory change, such as oxygen consumption per unit time.
カード 157
質問
How does a noncompetitive inhibitor act?
回答
It binds away from the active site and changes enzyme activity, often by altering shape.
カード 158
質問
What products of the light reactions feed the Calvin cycle?
回答
ATP and NADPH.
カード 159
質問
How does electron transport create a proton gradient?
回答
Released electron energy pumps protons from the matrix to the intermembrane space.
カード 160
質問
What do NADH and FADH₂ carry?
回答
High-energy electrons and associated hydrogen used in energy-transfer pathways.
カード 161
質問
What is allosteric regulation?
回答
A regulator binds at one site and changes activity at another site on the protein.
カード 162
質問
What does carbon fixation accomplish?
回答
It incorporates inorganic carbon dioxide into an organic molecule.
カード 163
質問
What is oxidative phosphorylation?
回答
ATP production powered by electron transport and chemiosmosis.
カード 164
質問
Why use multiple biological replicates in a rate experiment?
回答
They reveal natural variation and make the estimated treatment effect more reliable.
カード 165
質問
What is fermentation's central purpose?
回答
It regenerates NAD⁺ so glycolysis can continue without an active electron transport chain.
カード 166
質問
How does feedback inhibition control a pathway?
回答
A pathway's end product inhibits an earlier enzyme, reducing unnecessary production.
カード 167
質問
What enzyme fixes carbon in the Calvin cycle?
回答
Rubisco.
カード 168
質問
How does mitochondrial ATP synthase make ATP?
回答
Protons flow into the matrix through ATP synthase, driving ADP phosphorylation.
カード 169
質問
Why do cells use stepwise electron transfers?
回答
They release energy in manageable increments that can be captured instead of lost mostly as heat.
カード 170
質問
What is a cofactor?
回答
A nonprotein helper, often a metal ion or small organic coenzyme, required for some enzymes to function.
カード 171
質問
What are the three broad phases of the Calvin cycle?
回答
Carbon fixation, reduction, and regeneration of the carbon-dioxide acceptor RuBP.
カード 172
質問
How does lactic-acid fermentation regenerate NAD⁺?
回答
NADH reduces pyruvate to lactate, returning electrons to form NAD⁺.
カード 173
質問
What is substrate-level phosphorylation?
回答
An enzyme transfers a phosphate directly from an intermediate to ADP.
カード 174
質問
Error bars overlap broadly between two treatments. What is a careful conclusion?
回答
The graph alone does not show a clear difference; a suitable statistical analysis and design context are still needed.
カード 175
質問
Why run an enzyme assay without enzyme?
回答
It measures the uncatalyzed background change and tests whether enzyme is required.
カード 176
質問
How does alcoholic fermentation regenerate NAD⁺?
回答
Pyruvate loses carbon dioxide, and the remaining compound is reduced to ethanol as NADH becomes NAD⁺.
カード 177
質問
What is G3P's role in photosynthesis?
回答
It is a three-carbon product that can leave the Calvin cycle and help build carbohydrates.
カード 178
質問
Why are mitochondrial cristae useful?
回答
They increase inner-membrane area for electron transport chains and ATP synthase.
カード 179
質問
What does phosphorylation often do to a molecule?
回答
It adds a phosphate group that can increase reactivity or alter a protein's shape and activity.
カード 180
質問
A mutation lowers an enzyme's maximum rate but not substrate binding. What is a plausible effect?
回答
It may impair a catalytic step or reduce the number of functional enzyme molecules.
カード 181
質問
Why must the Calvin cycle regenerate RuBP?
回答
RuBP is the carbon-dioxide acceptor needed for another turn of fixation.
カード 182
質問
A chemical lowers oxygen use but not glycolysis. Which stage is most directly implicated?
回答
Aerobic electron transport or a process supplying it, because glycolysis itself does not consume oxygen.
カード 183
質問
How would closed stomata affect photosynthesis?
回答
Carbon dioxide entry falls, which can limit carbon fixation even when light is available.
カード 184
質問
A plant receives green light only. Predict its photosynthetic rate.
回答
It will usually be lower than under equally intense red or blue light because common chlorophylls absorb green poorly.
カード 185
質問
Why does fermentation yield less ATP per glucose than aerobic respiration?
回答
It relies on glycolysis alone and leaves much of glucose's chemical energy in reduced end products.
カード 186
質問
How does low ATP affect respiration pathway activity?
回答
It usually relieves inhibition of key enzymes, increasing fuel oxidation and ATP production.
カード 187
質問
How can oxygen production estimate photosynthetic rate?
回答
Oxygen is a light-reaction product, so its production per unit time can serve as a rate proxy under controlled conditions.
カード 188
質問
What happens to electron transport if oxygen is removed?
回答
The chain backs up because electrons lack a final acceptor; NADH accumulates and oxidative phosphorylation stops.
カード 189
質問
Why does a light-response curve eventually level off?
回答
Another factor, such as carbon dioxide supply, temperature, or enzyme capacity, becomes limiting.
カード 190
質問
An uncoupler lets protons cross the inner mitochondrial membrane. What happens?
回答
The gradient weakens, ATP production falls, and more energy is released as heat even if electron transport continues.
カード 191
質問
What is direct-contact signaling?
回答
A membrane-bound molecule or cell junction communicates with an adjacent cell.
カード 192
質問
What are the three broad stages of cell signaling?
回答
Reception, transduction, and response.
カード 193
質問
How can a receptor mutation block a response even when ligand is present?
回答
The receptor may fail to bind ligand, change shape, or activate the first relay protein.
カード 194
質問
What is negative feedback?
回答
A response reduces the original stimulus, helping stabilize a variable near a functional range.
カード 195
質問
What happens during G1 phase?
回答
The cell grows, performs normal functions, and prepares for DNA replication.
カード 196
質問
Cells show response values of 2, 7, and 18 after rising ligand doses. Describe the trend.
回答
The response increases with ligand dose across the tested range.
カード 197
質問
What happens during reception?
回答
A ligand binds its receptor and changes the receptor's activity or shape.
カード 198
質問
What is paracrine signaling?
回答
A cell releases a local regulator that acts on nearby target cells.
カード 199
質問
What happens during S phase?
回答
DNA is replicated, producing sister chromatids for each chromosome.
カード 200
質問
A response occurs without ligand. What pathway defect is plausible?
回答
A receptor or downstream relay protein may be constitutively active.
カード 201
質問
What happens during signal transduction?
回答
Intracellular steps relay and often amplify information from the activated receptor.
カード 202
質問
What is synaptic signaling?
回答
A neuron releases neurotransmitter across a short synaptic gap to a target cell.
カード 203
質問
What happens during G2 phase?
回答
The cell grows, checks replicated DNA, and prepares the machinery for division.
カード 204
質問
Why compare receptor-positive and receptor-negative cells?
回答
The comparison tests whether the receptor is necessary for the observed response.
カード 205
質問
What counts as a cellular response?
回答
A change in gene expression, enzyme activity, ion flow, secretion, movement, division, or another cell behavior.
カード 206
質問
How does insulin participate in negative feedback?
回答
High blood glucose promotes insulin release, which lowers blood glucose and reduces the original stimulus.
カード 207
質問
What happens during mitosis?
回答
A eukaryotic nucleus separates duplicated chromosomes into two nuclei.
カード 208
質問
What is endocrine signaling?
回答
Hormones travel through circulatory fluid to target cells that may be far away.
カード 209
質問
What does a protein kinase do?
回答
It transfers a phosphate from ATP to a target protein.
カード 210
質問
A drug blocks a kinase, and the final response disappears. What is supported?
回答
The kinase is required somewhere in that pathway under the tested conditions.
カード 211
質問
What happens during cytokinesis?
回答
The cytoplasm divides to form separate daughter cells.
カード 212
質問
How does glucagon participate in glucose homeostasis?
回答
Low blood glucose promotes glucagon release, which raises blood glucose toward the normal range.
カード 213
質問
What does a protein phosphatase do?
回答
It removes a phosphate group from a target protein.
カード 214
質問
What is a ligand?
回答
A signaling molecule that binds specifically to a receptor.
カード 215
質問
What is the G1 checkpoint's broad role?
回答
It checks size, nutrients, growth signals, and DNA condition before replication.
カード 216
質問
Why can't one inhibitor experiment prove a protein's exact pathway position?
回答
Off-target effects and indirect dependencies can produce the same outcome.
カード 217
質問
Why are phosphorylation cascades reversible?
回答
Kinases add phosphates, while phosphatases remove them and reset pathway components.
カード 218
質問
What is positive feedback?
回答
A response strengthens the initiating stimulus until a separate event stops the loop.
カード 219
質問
What is the G2 checkpoint's broad role?
回答
It checks whether DNA replication is complete and damage is repaired before mitosis.
カード 220
質問
Why don't all cells respond to the same hormone?
回答
Only cells with a compatible receptor and response machinery can respond.
カード 221
質問
What is a second messenger?
回答
A small intracellular molecule or ion that relays a signal after receptor activation.
カード 222
質問
How can rescue with an active downstream protein map a pathway?
回答
If the response returns despite an upstream block, the rescued protein likely acts downstream of that block.
カード 223
質問
What does the spindle checkpoint verify?
回答
Every chromosome is correctly attached to spindle microtubules before sister chromatids separate.
カード 224
質問
Why is blood clotting a positive-feedback process?
回答
Activated platelets recruit and activate more platelets until the break is sealed.
カード 225
質問
Name two common second messengers.
回答
Cyclic AMP and calcium ions.
カード 226
質問
A mutant receptor binds ligand but never becomes phosphorylated. Predict downstream signaling.
回答
It will likely fall or disappear if receptor phosphorylation is required to recruit relay proteins.
カード 227
質問
How do cyclins regulate the cell cycle?
回答
Their concentrations rise and fall, activating cyclin-dependent kinases at specific stages.
カード 228
質問
Why must DNA replicate before mitosis?
回答
Each daughter nucleus needs a complete copy of the genome.
カード 229
質問
Where do receptors for many peptide hormones sit?
回答
In the plasma membrane, because these polar ligands do not readily cross the lipid bilayer.
カード 230
質問
How can a signaling pathway amplify a weak signal?
回答
One activated component activates many downstream molecules at successive steps.
カード 231
質問
What is the dependent variable in a ligand-dose experiment?
回答
The measured response, such as reporter activity, enzyme phosphorylation, or ion concentration.
カード 232
質問
What do cyclin-dependent kinases do?
回答
When paired with cyclins, they phosphorylate targets that drive cell-cycle transitions.
カード 233
質問
Why doesn't positive feedback usually maintain homeostasis by itself?
回答
It drives change away from the starting state and needs an external stop.
カード 234
質問
What is a G protein's signaling role?
回答
It switches activity when bound to GTP and relays information from certain membrane receptors to effectors.
カード 235
質問
How would you test whether calcium is required for a response?
回答
Block the calcium rise while keeping other conditions matched, then compare the response with a vehicle control.
カード 236
質問
What is apoptosis?
回答
Programmed cell death that dismantles a cell in a controlled way.
カード 237
質問
Where are receptors for many steroid hormones?
回答
Inside the cell, where lipid-soluble hormones can bind after crossing the membrane.
カード 238
質問
How can an ion-channel receptor create a rapid response?
回答
Ligand binding opens or closes a pore, quickly changing ion movement and membrane conditions.
カード 239
質問
Why test several ligand concentrations?
回答
A dose–response series can reveal sensitivity, saturation, and whether effects scale with ligand.
カード 240
質問
Why is apoptosis useful in multicellular organisms?
回答
It removes damaged, infected, or unneeded cells with limited harm to neighbors.
カード 241
質問
A thermostat-like pathway overshoots repeatedly. What defect is plausible?
回答
Delayed sensing or response can make negative feedback correct too late.
カード 242
質問
How can an intracellular receptor affect gene expression?
回答
The ligand–receptor complex can act directly or indirectly as a transcription regulator.
カード 243
質問
Cells lacking protein X divide despite DNA damage. Justify a checkpoint claim.
回答
Protein X likely supports a DNA-damage checkpoint because its absence links damage with continued division; rescue or pathway tests would strengthen the claim.
カード 244
質問
What aligns at the metaphase plate?
回答
Duplicated chromosomes attached to spindle microtubules from opposite poles.
カード 245
質問
How can failed checkpoints contribute to cancer?
回答
Cells with damage or abnormal signals can keep dividing instead of pausing or dying.
カード 246
質問
How can gap junctions support communication?
回答
They connect neighboring animal-cell cytoplasms so small molecules and ions can pass directly.
カード 247
質問
Why can the same ligand trigger different responses in two cell types?
回答
The cells can express different receptors, relay proteins, targets, or genes.
カード 248
質問
Two pathways share one relay protein. What can happen if that protein is blocked?
回答
Both responses may weaken, showing pathway crosstalk or a shared component.
カード 249
質問
During which mitotic stage do sister chromatids separate?
回答
Anaphase.
カード 250
質問
What defines a malignant tumor?
回答
Its cells invade surrounding tissue and may spread to distant sites.
カード 251
質問
How would loss of a feedback inhibitor affect a biosynthetic pathway?
回答
The pathway may stay active and overproduce its end product.
カード 252
質問
What ends a signaling response?
回答
Ligand removal, receptor inactivation, GTP hydrolysis, messenger breakdown, or dephosphorylation can shut it down.
カード 253
質問
A pathway diagram shows A activates B, and B inhibits C. Predict C after A activation.
回答
C activity should decrease, assuming the shown links are the relevant controlling interactions.
カード 254
質問
A phosphatase that normally turns off an activated relay protein is inhibited. Predict the effect on that pathway.
回答
Phosphorylated targets may stay active longer, extending or strengthening the response.
カード 255
質問
A drug prevents spindle formation. Where should the cycle stop?
回答
At the spindle checkpoint before anaphase, because chromosomes cannot attach correctly.
カード 256
質問
What is the purpose of meiosis?
回答
It produces haploid cells and reshuffles inherited alleles for sexual reproduction.
カード 257
質問
What is crossing over?
回答
Exchange of corresponding DNA segments between nonsister chromatids of homologous chromosomes.
カード 258
質問
What does Mendel's law of segregation describe?
回答
An individual's two alleles for a gene separate into different gametes.
カード 259
質問
Why do X-linked recessive traits often appear more frequently in XY individuals?
回答
They have only one X chromosome, so one recessive allele on it can determine the phenotype.
カード 260
質問
What is incomplete dominance?
回答
The heterozygote has a phenotype intermediate between the two homozygotes.
カード 261
質問
What does a chi-square goodness-of-fit test compare?
回答
Observed category counts with counts expected under a stated model.
カード 262
質問
What is a homologous chromosome pair?
回答
Two chromosomes carrying the same gene locations, one inherited from each parent, possibly with different alleles.
カード 263
質問
What does Mendel's law of independent assortment describe?
回答
Alleles of genes on different chromosomes, or far apart on one chromosome, assort independently during gamete formation.
カード 264
質問
What is genetic linkage?
回答
Genes close together on the same chromosome tend to be inherited together.
カード 265
質問
When does crossing over occur?
回答
During prophase I after homologs pair.
カード 266
質問
How do sister chromatids differ from homologous chromosomes?
回答
Sister chromatids are replicated copies of one chromosome; homologs are the maternal and paternal versions of the same chromosome type.
カード 267
質問
For Aa × Aa, what is the expected genotype ratio?
回答
1 AA : 2 Aa : 1 aa.
カード 268
質問
How can linked genes produce recombinant offspring?
回答
Crossing over can exchange DNA between the gene locations.
カード 269
質問
What is the usual null hypothesis for a Mendelian chi-square test?
回答
Any difference between observed and expected counts is due to chance sampling under the proposed inheritance model.
カード 270
質問
What happens to homologous chromosomes in meiosis I?
回答
They pair and then separate into different cells.
カード 271
質問
For Aa × Aa with complete dominance, what is the expected phenotype ratio?
回答
3 dominant phenotype : 1 recessive phenotype.
カード 272
質問
How does crossing over increase variation?
回答
It creates chromosomes with new combinations of parental alleles.
カード 273
質問
What does recombination frequency estimate?
回答
Relative distance between linked genes; higher frequency generally means greater separation, up to the 50% limit.
カード 274
質問
What happens to sister chromatids in meiosis II?
回答
Their centromeres separate, and the chromatids move into different cells.
カード 275
質問
What rule finds the probability of either of two mutually exclusive outcomes?
回答
Add their individual probabilities.
カード 276
質問
What is codominance?
回答
Both alleles contribute distinct, detectable products or traits in the heterozygote.
カード 277
質問
How is a chi-square contribution calculated for one category?
回答
Subtract expected from observed, square the difference, and divide by expected.
カード 278
質問
When do homologous chromosomes pair as tetrads?
回答
During prophase I.
カード 279
質問
What rule finds the probability that independent events both occur?
回答
Multiply their individual probabilities.
カード 280
質問
What is independent assortment?
回答
Each homologous pair orients independently at metaphase I, producing many maternal–paternal chromosome combinations.
カード 281
質問
Why can't recombination frequency exceed 50%?
回答
At 50%, recombinant and parental combinations are equally common and the genes behave as if unlinked.
カード 282
質問
What aligns at the metaphase I plate?
回答
Homologous pairs, with each homolog attached toward an opposite pole.
カード 283
質問
What is a test cross?
回答
Crossing an individual with a dominant phenotype to a homozygous recessive individual to infer the unknown genotype.
カード 284
質問
How can one gene have multiple alleles?
回答
More than two allele forms can exist in the population, although one diploid individual carries at most two.
カード 285
質問
How are total chi-square and category contributions related?
回答
Total chi-square is the sum of all category contributions.
カード 286
質問
What separates during anaphase I?
回答
Homologous chromosomes; sister chromatids remain joined.
カード 287
質問
How does random fertilization increase variation?
回答
Any one genetically varied gamete from one parent can fuse with any compatible gamete from the other.
カード 288
質問
A test cross yields about half recessive offspring. What genotype is supported for the unknown parent?
回答
Heterozygous.
カード 289
質問
What is nondisjunction?
回答
Failure of homologous chromosomes or sister chromatids to separate normally.
カード 290
質問
What aligns during metaphase II?
回答
Individual duplicated chromosomes in each haploid cell.
カード 291
質問
What is polygenic inheritance?
回答
Multiple genes contribute to one trait, often producing continuous phenotypic variation.
カード 292
質問
For a simple goodness-of-fit test, how are degrees of freedom found?
回答
Number of categories minus one.
カード 293
質問
Which meiotic events create variation before fertilization?
回答
Crossing over and independent assortment.
カード 294
質問
How does ploidy change during meiosis?
回答
Homolog separation reduces diploid cells to haploid cells; meiosis II separates chromatids without another ploidy reduction.
カード 295
質問
What pedigree pattern often suggests a recessive trait?
回答
Unaffected parents can have an affected child, if both parents carry the allele.
カード 296
質問
How can meiotic nondisjunction affect gametes?
回答
It can produce gametes with an extra or missing chromosome.
カード 297
質問
What is pleiotropy?
回答
One gene influences multiple phenotypic traits.
カード 298
質問
Why is there no second DNA replication before meiosis II?
回答
The goal is to separate existing sister chromatids, not duplicate the genome again.
カード 299
質問
What does a p-value below the chosen threshold support?
回答
Rejecting the null model because the observed deviation would be unlikely if that model were correct.
カード 300
質問
Why are siblings genetically different even with the same parents?
回答
They inherit different allele combinations through crossing over, independent assortment, and random fertilization.
カード 301
質問
Why do small families often deviate from expected Mendelian ratios?
回答
Probability ratios describe long-run expectations; random sampling variation is large with few offspring.
カード 302
質問
A diploid cell has six chromosomes. How many chromosomes should each normal meiotic product have?
回答
Three.
カード 303
質問
A trisomic zygote forms after fertilization. What meiotic error is a likely cause?
回答
Nondisjunction produced a gamete carrying an extra copy of that chromosome.
カード 304
質問
Why can identical genotypes show different phenotypes?
回答
Environmental conditions and developmental variation can alter gene expression or trait development.
カード 305
質問
What does failing to reject a genetic null hypothesis mean?
回答
The data do not show a significant departure from the model; they do not prove the model true.
カード 306
質問
How do DNA and RNA sugars differ?
回答
DNA contains deoxyribose; RNA contains ribose.
カード 307
質問
What does semiconservative DNA replication produce?
回答
Each daughter DNA molecule contains one original strand and one newly synthesized strand.
カード 308
質問
What is transcription?
回答
Synthesis of RNA using DNA as a template.
カード 309
質問
What is a point mutation?
回答
A change affecting one nucleotide pair.
カード 310
質問
What is an operon?
回答
A group of prokaryotic genes controlled together and transcribed from one promoter.
カード 311
質問
Why can muscle and nerve cells differ despite having the same genome?
回答
They express different sets and amounts of genes.
カード 312
質問
What must a virus use from its host?
回答
Host resources and at least some host-cell machinery to copy or express its genome and produce new particles.
カード 313
質問
What does PCR do?
回答
It amplifies a chosen DNA region through repeated cycles of strand separation, primer binding, and extension.
カード 314
質問
What enzyme performs transcription?
回答
RNA polymerase.
カード 315
質問
What does helicase do during replication?
回答
It unwinds the double helix and separates the template strands.
カード 316
質問
How does a repressor reduce transcription?
回答
It binds regulatory DNA and blocks or hinders transcription machinery.
カード 317
質問
What is a silent mutation?
回答
A nucleotide change that does not change the encoded amino acid.
カード 318
質問
What does a promoter do?
回答
It marks where transcription machinery assembles and helps set the transcription start and direction.
カード 319
質問
What does topoisomerase do ahead of a replication fork?
回答
It relieves twisting strain caused by DNA unwinding.
カード 320
質問
How does an inducer affect an inducible operon?
回答
It disables the repressor or otherwise turns transcription on when the pathway's substrate is present.
カード 321
質問
How do DNA and RNA bases differ?
回答
DNA uses thymine, while RNA uses uracil; both also use adenine, cytosine, and guanine.
カード 322
質問
Which DNA strand does RNA polymerase read?
回答
The template strand, read 3′→5′ while RNA is built 5′→3′.
カード 323
質問
Why is an RNA primer needed for DNA replication?
回答
DNA polymerase can extend an existing 3′ end but cannot start a strand from nothing.
カード 324
質問
How does a corepressor affect a repressible operon?
回答
It activates a repressor, turning off genes when the pathway's end product is abundant.
カード 325
質問
What is a missense mutation?
回答
A nucleotide change that substitutes one amino acid for another.
カード 326
質問
How does an mRNA sequence relate to the coding DNA strand?
回答
It matches the coding strand except RNA has uracil in place of thymine.
カード 327
質問
What does primase do?
回答
It builds short RNA primers.
カード 328
質問
Why is the lac operon strongly expressed when lactose is present and glucose is scarce?
回答
Lactose relieves repression, while low glucose supports positive activation of transcription.
カード 329
質問
Why are primers essential in PCR?
回答
They define the target boundaries and provide 3′ ends for DNA polymerase.
カード 330
質問
What is the primary RNA transcript in a eukaryote?
回答
The initial RNA copy before processing.
カード 331
質問
In which direction does DNA polymerase synthesize DNA?
回答
5′→3′ by adding nucleotides to a 3′ end.
カード 332
質問
Why is the trp operon usually off when tryptophan is abundant?
回答
Tryptophan acts as a corepressor, enabling repression of biosynthetic genes.
カード 333
質問
What holds complementary DNA bases together?
回答
Hydrogen bonds: adenine pairs with thymine, and cytosine pairs with guanine.
カード 334
質問
What happens during RNA splicing?
回答
Introns are removed and exons are joined.
カード 335
質問
Why is the leading strand synthesized continuously?
回答
Its template orientation lets polymerase follow the replication fork while synthesizing 5′→3′.
カード 336
質問
How can histone acetylation affect transcription?
回答
It often loosens chromatin and makes DNA more accessible to transcription machinery.
カード 337
質問
What is a nonsense mutation?
回答
A nucleotide change that creates a premature stop codon.
カード 338
質問
What do the 5′ cap and poly-A tail help do?
回答
They protect eukaryotic mRNA and support export and translation.
カード 339
質問
Why is the lagging strand synthesized in fragments?
回答
Its template orientation forces repeated 5′→3′ synthesis away from the moving fork.
カード 340
質問
How can DNA methylation near a promoter affect transcription?
回答
It often reduces transcription by limiting access or recruiting repressive proteins.
カード 341
質問
How does gel electrophoresis separate DNA fragments?
回答
An electric field pulls negatively charged DNA through a matrix; smaller fragments usually travel farther.
カード 342
質問
How can alternative splicing increase protein diversity?
回答
Different exon combinations from one transcript can produce different mRNAs and polypeptides.
カード 343
質問
What are Okazaki fragments?
回答
Short DNA segments made on the lagging strand.
カード 344
質問
What does a transcription factor do?
回答
It binds regulatory DNA and helps increase or decrease transcription of specific genes.
カード 345
質問
Why are DNA strands antiparallel?
回答
Their sugar–phosphate backbones run in opposite 5′→3′ directions.
カード 346
質問
What is translation?
回答
Ribosomes use an mRNA codon sequence to build a polypeptide.
カード 347
質問
What does DNA ligase do?
回答
It seals breaks in the sugar–phosphate backbone, joining DNA fragments.
カード 348
質問
What is a frameshift mutation?
回答
An insertion or deletion not in multiples of three that shifts downstream codon grouping.
カード 349
質問
How can an enhancer influence a distant promoter?
回答
DNA looping brings enhancer-bound activators near the transcription machinery.
カード 350
質問
What does a codon specify?
回答
An amino acid or a translation stop signal.
カード 351
質問
What do restriction enzymes do?
回答
They cut DNA at particular recognition sequences.
カード 352
質問
What gives a nucleic-acid strand its 5′ and 3′ ends?
回答
The chemical groups on the sugar: a 5′ phosphate end and a 3′ hydroxyl end.
カード 353
質問
How does proofreading improve replication accuracy?
回答
DNA polymerases detect and replace many incorrectly paired nucleotides.
カード 354
質問
What does a tRNA anticodon do?
回答
It base-pairs with an mRNA codon so the attached amino acid is placed correctly.
カード 355
質問
Why can a promoter mutation affect protein amount?
回答
It can change transcription-factor or RNA-polymerase binding and alter transcription rate.
カード 356
質問
How can microRNA reduce gene expression?
回答
It base-pairs with target mRNA and promotes degradation or blocks translation.
カード 357
質問
What maintains a differentiated cell's identity?
回答
Stable regulatory networks and chromatin states keep characteristic genes active or silent.
カード 358
質問
What are the ribosome's broad roles?
回答
It positions mRNA and tRNAs and catalyzes peptide-bond formation.
カード 359
質問
How can an RNA virus generate genetic variation quickly?
回答
Many viral RNA polymerases lack strong proofreading, so replication introduces mutations frequently.
カード 360
質問
What can bacterial transformation demonstrate?
回答
Cells can take up external DNA and express a selectable or observable trait.
カード 361
質問
Why is RNA usually more structurally varied than double-stranded DNA?
回答
A single RNA strand can fold back on itself through internal base pairing.
カード 362
質問
What usually marks translation initiation?
回答
A start codon positioned with an initiator tRNA and ribosomal subunits.
カード 363
質問
What problem do telomeres help solve?
回答
They protect chromosome ends from losing essential genes during repeated linear-DNA replication.
カード 364
質問
Why can an intron splice-site mutation affect protein sequence?
回答
Incorrect splicing can remove exon sequence or retain intron sequence in the mature mRNA.
カード 365
質問
How can protein degradation regulate a pathway quickly?
回答
Destroying a key protein lowers its activity without waiting for transcription to change.
カード 366
質問
What happens at a stop codon?
回答
A release factor ends translation and frees the polypeptide.
カード 367
質問
How can a signal change cell specialization?
回答
It can activate transcription factors that launch a new gene-expression program.
カード 368
質問
What is a retrovirus's information flow?
回答
Viral RNA is reverse-transcribed into DNA, which can integrate into the host genome.
カード 369
質問
What does DNA sequencing reveal directly?
回答
The order of nucleotides in the analyzed DNA; biological effects require further interpretation.
カード 370
質問
Why is the genetic code called redundant?
回答
More than one codon can specify the same amino acid.
カード 371
質問
Where does nucleotide sequence store information?
回答
The order of bases encodes information that can be copied, transcribed, or translated.
カード 372
質問
Why is replication called bidirectional?
回答
Two forks usually move away from each origin in opposite directions.
カード 373
質問
Why doesn't every DNA mutation change phenotype?
回答
It may occur outside a functional sequence, be silent, have a mild effect, or be masked by another allele or environment.
カード 374
質問
How does a free ribosome's product usually differ from a rough-ER ribosome's product?
回答
Free ribosomes often make cytosolic proteins; ER-bound ribosomes make many secreted, membrane, and endomembrane proteins.
カード 375
質問
Why can one signal coordinate many genes?
回答
A shared transcription regulator or signaling pathway can control multiple target promoters.
カード 376
質問
Why does cell specialization depend on selective gene expression rather than gene loss?
回答
Most specialized cells retain the genome but use only the genes needed for their role.
カード 377
質問
Why are viruses not described as independently living cells?
回答
They lack cellular metabolism and cannot reproduce without a host cell.
カード 378
質問
A coding DNA triplet is 5′-ATG-3′. What is the matching mRNA codon?
回答
5′-AUG-3′.
カード 379
質問
A PCR band is absent. Why isn't gene absence the only explanation?
回答
Poor DNA quality, wrong primers, inhibitors, or failed reaction conditions can also prevent amplification.
カード 380
質問
Why can protein function require steps after translation?
回答
The polypeptide may need folding, cleavage, chemical modification, or assembly with other subunits.
カード 381
質問
How do fossils support evolution?
回答
They document organisms and transitions through time, including appearance, change, and extinction.
カード 382
質問
What conditions are required for natural selection?
回答
Individuals vary, some variation is heritable, and variants differ in survival or reproductive success in that environment.
カード 383
質問
What is artificial selection?
回答
Humans choose which organisms reproduce based on desired heritable traits.
カード 384
質問
What does an allele frequency measure?
回答
The fraction of all copies of a gene in a population represented by one allele.
カード 385
質問
What does a node on a phylogenetic tree represent?
回答
A common ancestor where descendant lineages diverge.
カード 386
質問
What is biological speciation?
回答
Evolution of reproductive isolation between populations, producing independently evolving lineages.
カード 387
質問
What is extinction?
回答
Permanent loss of a species when no living members remain.
カード 388
質問
A pesticide-treated population becomes mostly resistant. What evidence distinguishes selection from acclimation?
回答
Resistance should be heritable and increase across generations through differential reproduction, not just appear temporarily in exposed individuals.
カード 389
質問
What changes during evolution by natural selection?
回答
Allele frequencies in a population across generations.
カード 390
質問
For two alleles under Hardy–Weinberg notation, what does p + q equal?
回答
1.
カード 391
質問
What is a clade?
回答
An ancestor and all of its descendants.
カード 392
質問
What does homologous anatomy suggest?
回答
Similar underlying structures with different functions can indicate inheritance from a common ancestor.
カード 393
質問
Do individual organisms evolve by natural selection?
回答
No. Individuals are selected; populations evolve as inherited variants change in frequency.
カード 394
質問
Under Hardy–Weinberg equilibrium, what does p² represent?
回答
Expected frequency of one homozygous genotype.
カード 395
質問
What is a shared derived character?
回答
A trait that evolved in a common ancestor and helps identify one of its descendant clades.
カード 396
質問
What is mutation's evolutionary role?
回答
It creates new alleles, the ultimate source of new genetic variation.
カード 397
質問
What is biological fitness?
回答
Relative contribution of viable, reproducing offspring to the next generation in a particular environment.
カード 398
質問
Under Hardy–Weinberg equilibrium, what does 2pq represent?
回答
Expected frequency of heterozygotes.
カード 399
質問
Which two tips on a tree are most closely related?
回答
Those sharing the most recent common ancestor, regardless of how close their names appear on the page.
カード 400
質問
What is a vestigial structure?
回答
A reduced feature inherited from ancestors that has lost much or all of its earlier function.
カード 401
質問
What is an adaptation?
回答
A heritable trait that became common because it improved fitness in past environments.
カード 402
質問
Under Hardy–Weinberg equilibrium, what does q² represent?
回答
Expected frequency of the other homozygous genotype.
カード 403
質問
How does recombination affect evolution?
回答
It reshuffles existing alleles into new combinations but does not itself create new alleles.
カード 404
質問
Does rotating branches around a node change relationships?
回答
No. The branching pattern stays the same.
カード 405
質問
Why isn't an adaptation always beneficial in every setting?
回答
Fitness effects depend on the environment and can involve tradeoffs.
カード 406
質問
What are the Hardy–Weinberg assumptions?
回答
A very large population, random mating, no mutation, no migration, and no natural selection at the locus.
カード 407
質問
How can embryological similarities support common ancestry?
回答
Shared developmental patterns can reflect inherited developmental genes and pathways.
カード 408
質問
What is gene flow?
回答
Movement of alleles between populations through migration and reproduction.
カード 409
質問
Does natural selection create needed mutations?
回答
No. Mutations arise without regard to need; selection changes the frequencies of their inherited effects.
カード 410
質問
Why is Hardy–Weinberg equilibrium useful?
回答
It provides a null model for detecting or reasoning about evolutionary change.
カード 411
質問
Does left-to-right tip order show evolutionary progress?
回答
No. Tip order is a drawing choice, not a ranking from primitive to advanced.
カード 412
質問
What is allopatric speciation?
回答
Geographic separation reduces gene flow, allowing populations to diverge.
カード 413
質問
What is directional selection?
回答
Selection favors one end of a phenotypic range, shifting the population mean.
カード 414
質問
If q² = 0.09, what is q?
回答
0.30.
カード 415
質問
Why is DNA sequence similarity evidence for relatedness?
回答
Related lineages inherit sequences from common ancestors, with differences accumulating over time.
カード 416
質問
How does gene flow often affect differences between populations?
回答
It tends to make allele frequencies more similar.
カード 417
質問
What is stabilizing selection?
回答
Selection favors intermediate phenotypes and removes extremes.
カード 418
質問
If q = 0.30, what is p?
回答
0.70.
カード 419
質問
What can branch length mean?
回答
Only what the figure defines—sometimes time or amount of change, and sometimes nothing quantitative.
カード 420
質問
What is sympatric speciation?
回答
Reproductive isolation evolves without geographic separation, for example through polyploidy or strong niche and mating differences.
カード 421
質問
What is disruptive selection?
回答
Selection favors both extremes over intermediate phenotypes.
カード 422
質問
If p = 0.70 and q = 0.30, what is 2pq?
回答
0.42.
カード 423
質問
Why include an untreated population in a selection experiment?
回答
It shows how allele or trait frequencies change without the selective treatment.
カード 424
質問
Why is the nearly universal genetic code evidence of common ancestry?
回答
A deeply conserved information system is most simply explained by inheritance from early shared ancestors.
カード 425
質問
What is balancing selection?
回答
Natural selection that maintains two or more alleles in a population, such as through heterozygote advantage or selection that varies across environments.
カード 426
質問
What is genetic drift?
回答
Random change in allele frequencies caused by chance sampling across generations.
カード 427
質問
If 16% of a Hardy–Weinberg population shows a recessive phenotype, what is q?
回答
0.40, because q is the square root of 0.16.
カード 428
質問
Why use an outgroup in tree analysis?
回答
It helps infer which character states are ancestral versus derived in the focal group.
カード 429
質問
What is a prezygotic barrier?
回答
A barrier that prevents mating or fertilization.
カード 430
質問
Allele A rises from 0.20 to 0.45. Describe the evolutionary result.
回答
The population evolved at that locus because allele frequency changed.
カード 431
質問
How does biogeography support evolution?
回答
Species distributions often match isolation history, dispersal, and descent from nearby ancestors.
カード 432
質問
What is sexual selection?
回答
Differences in mating success drive changes in traits that affect mate attraction or competition.
カード 433
質問
When is genetic drift strongest?
回答
In small populations.
カード 434
質問
Why can a rare recessive allele persist?
回答
Selection cannot remove copies hidden in heterozygotes as efficiently as copies expressed in homozygotes.
カード 435
質問
How can molecular data revise a phylogenetic tree?
回答
Sequence comparisons can reveal relationships not obvious from morphology or distinguish convergence from homology.
カード 436
質問
What is a postzygotic barrier?
回答
A barrier that reduces hybrid survival, fertility, or later-generation success after fertilization.
カード 437
質問
How can rapid environmental change increase extinction risk?
回答
Populations may lack enough suitable variation or time to adapt or move.
カード 438
質問
A small island population loses alleles after a storm. Which mechanism is most direct?
回答
Genetic drift through a bottleneck.
カード 439
質問
What is convergent evolution?
回答
Unrelated lineages independently evolve similar traits under similar selective pressures.
カード 440
質問
Why can antibiotic resistance spread rapidly?
回答
Treatment strongly favors resistant variants already present or newly introduced, which leave more descendants.
カード 441
質問
What is a bottleneck effect?
回答
A sharp population reduction leaves a random, often less diverse sample of the original gene pool.
カード 442
質問
How do genotype counts yield allele frequency?
回答
Count two copies from each homozygote and one from each heterozygote, then divide by twice the number of diploid individuals.
カード 443
質問
What is maximum parsimony in tree building?
回答
Preferring the tree that requires the fewest evolutionary changes under the model.
カード 444
質問
How can different breeding times isolate populations?
回答
Temporal isolation prevents individuals from mating even when they share a location.
カード 445
質問
Why can mass extinctions reshape evolution?
回答
They remove many lineages and open ecological opportunities for survivors.
カード 446
質問
Two similar traits evolved on distant tree branches. What explanation should be evaluated?
回答
Convergent evolution under similar selection, alongside the possibility of an incorrect tree or unrecognized homology.
カード 447
質問
Why are analogous structures weak evidence of close ancestry?
回答
Their similar function may have evolved independently rather than from the same ancestral structure.
カード 448
質問
Why doesn't natural selection produce perfection?
回答
It works with existing variation under tradeoffs, historical constraints, chance, and changing environments.
カード 449
質問
What is a founder effect?
回答
A new population starts from a small, nonrepresentative sample of a source population.
カード 450
質問
Observed genotypes differ from Hardy–Weinberg expectations. What is supported?
回答
At least one model assumption may not hold, or sampling error may matter; the deviation alone does not identify the cause.
カード 451
質問
Why is a phylogenetic tree a hypothesis?
回答
It is an evidence-based reconstruction that can change when new data or methods appear.
カード 452
質問
How can behavioral differences cause isolation?
回答
Different courtship signals reduce mating between populations.
カード 453
質問
What evidence can test origin-of-life hypotheses?
回答
Chemistry experiments, geological records, molecular comparisons, and plausible self-replicating or membrane-forming systems.
カード 454
質問
How should fitness be compared in an experiment?
回答
Measure relative reproductive contribution, such as viable offspring, under the same environmental conditions.
カード 455
質問
What does the fossil record not provide?
回答
A complete sample of every organism or every transitional population.
カード 456
質問
How can a neutral trait change in frequency?
回答
Genetic drift can shift it by chance, especially in small populations.
カード 457
質問
How can drift reduce adaptive potential?
回答
It can remove alleles and lower genetic diversity needed under future environmental change.
カード 458
質問
Why does a large population support Hardy–Weinberg stability?
回答
Chance sampling has less effect on allele frequencies, reducing drift.
カード 459
質問
If A and B share a more recent node with each other than either shares with C, what does that mean?
回答
A and B are sister taxa and share a more recent common ancestor with each other than with C.
カード 460
質問
What is adaptive radiation?
回答
Rapid diversification of one ancestral lineage into species using different ecological roles.
カード 461
質問
What can experiments producing organic molecules from simple chemicals show?
回答
That some building blocks can form under modeled conditions; they do not recreate or prove the exact origin of life.
カード 462
質問
A correlation links beak size with survival. Why isn't causation settled?
回答
Other traits or habitats may covary with beak size; controlled or multivariable evidence is needed.
カード 463
質問
Why does agreement among fossils, anatomy, and molecules strengthen an evolutionary claim?
回答
Independent evidence types pointing to the same history make alternative explanations less plausible.
カード 464
質問
A drought favors deeper beaks. What must be measured to show selection?
回答
Heritable beak variation and differences in survival or reproduction linked to beak depth.
カード 465
質問
Why can artificial selection produce unintended traits?
回答
Selected genes may be linked to other alleles, and inbreeding can expose harmful recessive alleles.
カード 466
質問
What data are needed to test Hardy–Weinberg genotype expectations?
回答
Population genotype counts or reliable genotype frequencies for the locus.
カード 467
質問
Why doesn't one living species count as the ancestor of another on a typical tree?
回答
Living tips represent lineages that have both evolved since their shared ancestral lineage.
カード 468
質問
Why can reduced gene flow accelerate divergence?
回答
Populations retain separate mutations, drift independently, and respond to different selective pressures.
カード 469
質問
Why are ribozymes relevant to early-life hypotheses?
回答
RNA can both store information and catalyze reactions, offering a possible bridge before modern DNA–protein systems.
カード 470
質問
What makes an evolutionary argument strong?
回答
A clear claim, relevant population-level evidence, and reasoning that connects inheritance and differential reproduction to the observed change.
カード 471
質問
How can a directional response help an organism?
回答
Moving toward resources or away from hazards can improve survival and reproduction.
カード 472
質問
What is a trophic level?
回答
A feeding position in the flow of energy through an ecosystem.
カード 473
質問
What processes move carbon into and out of biological molecules?
回答
Photosynthesis fixes carbon; respiration, decomposition, and combustion release carbon dioxide.
カード 474
質問
What does exponential population growth assume?
回答
Resources are effectively unlimited and the per-capita growth rate stays constant.
カード 475
質問
What is a density-dependent limiting factor?
回答
Its effect strengthens as population density rises, such as competition, disease, or predation.
カード 476
質問
What is a keystone species?
回答
A species whose ecological effect is disproportionately large relative to its abundance.
カード 477
質問
What are three levels of biodiversity?
回答
Genetic diversity, species diversity, and ecosystem diversity.
カード 478
質問
What is the independent variable in a fertilizer–algae experiment?
回答
The fertilizer amount or nutrient concentration deliberately changed.
カード 479
質問
What shape represents exponential growth over time?
回答
A J-shaped curve.
カード 480
質問
What do primary producers do?
回答
They capture external energy and build organic molecules from inorganic carbon.
カード 481
質問
What is a density-independent limiting factor?
回答
Its effect is not primarily set by population density, such as a severe freeze or wildfire.
カード 482
質問
Why is nitrogen fixation necessary?
回答
Most organisms cannot use atmospheric nitrogen gas directly, so it must be converted to biologically available compounds.
カード 483
質問
What does logistic growth add to the exponential model?
回答
Growth slows as population size approaches carrying capacity.
カード 484
質問
What is gross primary productivity?
回答
The total rate at which producers capture energy in organic matter.
カード 485
質問
What is competition?
回答
An interaction in which organisms using the same limited resource reduce one another's access or fitness.
カード 486
質問
What is ecological succession?
回答
Change in community composition after new habitat forms or a disturbance alters an existing community.
カード 487
質問
What shape represents ideal logistic growth?
回答
An S-shaped curve.
カード 488
質問
What is net primary productivity?
回答
Gross primary productivity minus producers' respiratory energy use.
カード 489
質問
Why does genetic diversity matter for conservation?
回答
It increases the range of inherited responses available under disease or environmental change.
カード 490
質問
What organisms perform much biological nitrogen fixation?
回答
Certain prokaryotes, including free-living and symbiotic bacteria.
カード 491
質問
What is carrying capacity?
回答
The population size an environment can sustain over time under current conditions.
カード 492
質問
Why is net primary productivity important to consumers?
回答
It is the producer biomass and energy available for growth and the next trophic levels.
カード 493
質問
What is competitive exclusion?
回答
Species with identical limiting-resource niches cannot coexist indefinitely under stable conditions.
カード 494
質問
How do primary and secondary succession differ?
回答
Primary succession begins without developed soil; secondary succession begins where soil remains.
カード 495
質問
Why can carrying capacity change?
回答
Resources, habitat, climate, competitors, disease, and disturbance can change.
カード 496
質問
Why does available energy decline up a food chain?
回答
Organisms use much energy for metabolism and lose it as heat and waste rather than storing it as biomass.
カード 497
質問
What is an ecosystem service?
回答
A benefit people receive from ecosystems, such as pollination, water purification, soil formation, or climate regulation.
カード 498
質問
What does nitrification do?
回答
Microbes oxidize ammonium to nitrite and then nitrate.
カード 499
質問
What does per-capita growth rate measure?
回答
Population change per individual per unit time.
カード 500
質問
What is ecological efficiency?
回答
The percentage of energy or production transferred from one trophic level to the next.
カード 501
質問
What is resource partitioning?
回答
Competing species use different resources, places, or times, reducing direct overlap.
カード 502
質問
What is resilience in an ecosystem?
回答
The ability to recover structure or function after disturbance.
カード 503
質問
How is population growth estimated from births, deaths, immigration, and emigration?
回答
Births + immigration − deaths − emigration.
カード 504
質問
If producers store 10,000 kJ and primary consumers receive 10%, how much do they receive?
回答
1,000 kJ.
カード 505
質問
How does habitat fragmentation affect populations?
回答
It shrinks and isolates habitat, reducing movement and gene flow while increasing edge effects.
カード 506
質問
Why sample several sites within each habitat?
回答
Replication captures spatial variation and reduces the chance that one unusual site drives the result.
カード 507
質問
A population grows from 200 to 230 in one year. What is its percent growth?
回答
15%, because the increase of 30 divided by 200 is 0.15.
カード 508
質問
What is a circadian rhythm?
回答
An internal roughly 24-hour cycle that environmental cues can reset.
カード 509
質問
Why are food webs more realistic than simple food chains?
回答
Most species eat or are eaten by multiple species, creating connected pathways.
カード 510
質問
What does denitrification do?
回答
Microbes convert nitrate to nitrogen gases, returning nitrogen to the atmosphere.
カード 511
質問
What characterizes an r-selected life-history strategy?
回答
Many offspring, early reproduction, and relatively low investment per offspring in variable environments.
カード 512
質問
What is mutualism?
回答
An interaction that benefits both species.
カード 513
質問
What is resistance in an ecosystem?
回答
The ability to remain relatively unchanged during disturbance.
カード 514
質問
How can climate change shift species ranges?
回答
Organisms track suitable temperature, moisture, seasons, or interacting species when movement is possible.
カード 515
質問
What characterizes a K-selected life-history strategy?
回答
Fewer offspring, later reproduction, and higher investment per offspring near carrying capacity.
カード 516
質問
A population curve levels near 800. What does the model suggest?
回答
About 800 is the carrying capacity under those measured conditions, not a permanent universal value.
カード 517
質問
How can seasonal cues affect reproduction?
回答
Changes such as day length can trigger hormonal and behavioral shifts timed to favorable conditions.
カード 518
質問
What role do decomposers play?
回答
They break down dead material and waste, returning nutrients to forms other organisms can use.
カード 519
質問
Why can phosphorus limit ecosystems?
回答
It is essential but often released slowly from rocks and lacks a large atmospheric gas phase.
カード 520
質問
What does a Type I survivorship curve show?
回答
High survival through early and middle life, followed by a steep decline at older ages.
カード 521
質問
What is commensalism?
回答
One species benefits while the other has no clear benefit or harm.
カード 522
質問
Why can diversity improve ecosystem stability?
回答
Multiple species or response types can keep functions going when one component declines.
カード 523
質問
Why can overharvesting destabilize a population?
回答
Removal faster than replacement lowers abundance and can alter age structure or genetic diversity.
カード 524
質問
Predator and prey peaks alternate over time. What can the graph establish?
回答
Their abundances covary with a lag; the graph alone cannot prove the predator caused every prey change.
カード 525
質問
What is acclimation?
回答
A reversible phenotypic adjustment by an individual to an environmental change.
カード 526
質問
Does energy cycle through an ecosystem?
回答
No. Energy flows through and is ultimately dissipated as heat; matter cycles.
カード 527
質問
How does the water cycle connect ecosystems?
回答
Evaporation, transpiration, condensation, precipitation, runoff, and infiltration move water and dissolved materials.
カード 528
質問
What does a Type II survivorship curve show?
回答
A roughly constant mortality risk across ages.
カード 529
質問
What is parasitism?
回答
A parasite benefits while reducing its host's fitness.
カード 530
質問
What is an invasive species?
回答
A nonnative species that spreads and causes ecological, economic, or human-health harm.
カード 531
質問
How can a wildlife corridor help fragmented populations?
回答
It supports movement, recolonization, and gene flow between habitat patches.
カード 532
質問
How should biodiversity be compared when sample effort differs?
回答
Standardize sampling effort or use a method that accounts for unequal effort before comparing.
カード 533
質問
How does acclimation differ from adaptation?
回答
Acclimation occurs within an individual; adaptation is an inherited population change across generations.
カード 534
質問
How can removal of a top predator affect lower trophic levels?
回答
It can trigger a trophic cascade by changing prey abundance and the organisms prey consume.
カード 535
質問
Why can extra fertilizer cause low oxygen in water?
回答
Nutrient enrichment drives algal growth; decomposition then consumes dissolved oxygen.
カード 536
質問
What does a Type III survivorship curve show?
回答
High early mortality with much better survival among those reaching later stages.
カード 537
質問
How can predation maintain diversity?
回答
A predator can prevent one strong competitor from dominating the community.
カード 538
質問
How can disturbance increase or decrease diversity?
回答
Its effect depends on frequency and intensity; it may create habitat variety or eliminate sensitive species.
カード 539
質問
Why protect multiple habitats rather than one small reserve?
回答
Different habitats, disturbances, and climate trajectories preserve more species and ecological options.
カード 540
質問
A restoration site gains species but not nutrient cycling. How should success be evaluated?
回答
Use both composition and ecosystem-function measures; one metric alone gives an incomplete result.
