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