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