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