Why is a water molecule polar?

Oxygen pulls shared electrons more strongly than hydrogen, giving oxygen a partial negative charge and the hydrogens partial positive charges.

Which elements make up most biological molecules?

Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur—often shortened to CHNOPS.

What is the relationship between a monomer and a polymer?

Monomers are small building blocks; polymers are chains or networks made from repeated monomers.

What is a monosaccharide's main role in cells?

It can provide quick energy and serve as a building block for larger carbohydrates.

Why do lipids mix poorly with water?

Most of their bonds are nonpolar, so water cannot form favorable interactions with them.

What three parts make up a nucleotide?

A five-carbon sugar, a phosphate group, and a nitrogenous base.

What parts of an amino acid vary and stay constant?

The amino group, carboxyl group, hydrogen, and central carbon are shared; the side chain, or R group, varies.

What does pH measure?

The negative logarithm of hydrogen-ion concentration; lower pH means more hydrogen ions.

What is a hydrogen bond in liquid water?

A weak attraction between a partially positive hydrogen on one water molecule and a partially negative oxygen on another.

How does an unsaturated fatty acid differ from a saturated one?

An unsaturated fatty acid has at least one carbon–carbon double bond; a saturated fatty acid has none.

What does dehydration synthesis do?

It joins subunits with a covalent bond while removing the elements of water.

How does cohesion help water move through a plant?

Hydrogen bonds keep water molecules linked, helping a continuous column rise through xylem.

How do plants and animals differ in short-term glucose storage?

Plants store glucose mainly as starch; animals store it mainly as glycogen.

How does a cis double bond affect a fatty-acid tail?

It introduces a bend that prevents neighboring tails from packing tightly.

How does adhesion support water transport in narrow tubes?

Water sticks to polar surfaces, helping it resist gravity along cell walls.

Which base pairing distinguishes RNA from DNA?

RNA uses uracil, so adenine pairs with uracil instead of thymine.

What stabilizes common protein secondary structures?

Hydrogen bonds between atoms in the polypeptide backbone.

Why can carbon form so many biological structures?

It has four valence electrons and can form four stable covalent bonds, including chains, branches, and rings.

Why can some insects stand on water?

Cohesion among surface water molecules creates high surface tension.

What does hydrolysis do to a biological polymer?

It adds the elements of water to break a covalent bond between subunits.

Why are fats useful for long-term energy storage?

Their many C–H bonds store substantial chemical energy, and hydrophobic storage adds little water mass.

How does water buffer rapid temperature change?

Breaking and forming many hydrogen bonds absorbs or releases substantial heat, giving water a high specific heat.

What does antiparallel mean for a DNA double helix?

Its two strands run in opposite directions: one 5′→3′ and the other 3′→5′.

What mainly drives a protein's tertiary structure?

Interactions among side chains, including hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bridges.

What is a trace element?

An element an organism needs in very small amounts, such as iron in many electron-transfer proteins.

Why does sweating cool an organism?

The fastest water molecules escape as vapor, carrying heat away from the surface.

A cell builds a polysaccharide from sugars. Is water consumed or released?

Released. Forming each linkage by dehydration removes water.

Why can branching help a storage polysaccharide release glucose quickly?

More branch ends give enzymes more sites to work at once.

What makes a phospholipid amphipathic?

It has a polar, hydrophilic head and nonpolar, hydrophobic tails.

Where is biological information encoded in a nucleic acid?

In the linear sequence of nucleotide bases.

What is quaternary protein structure?

The arrangement of two or more polypeptide subunits into one functional protein.

Why does ice float on liquid water?

Stable hydrogen bonds hold ice molecules in an open lattice, making ice less dense than liquid water.

How does electronegativity affect a covalent bond?

A difference in attraction for electrons makes electron sharing unequal and can create a polar bond.

Why do phospholipids form bilayers in water?

Hydrophilic heads face water while hydrophobic tails cluster away from it.

To which end are nucleotides added during nucleic-acid synthesis?

The 3′ end of the growing strand.

Why can one amino-acid substitution change protein function?

It can alter side-chain interactions, folding, stability, or an active or binding site.

How does a buffer resist a pH change?

It can accept added hydrogen ions or donate them when hydrogen-ion concentration falls.

Why is water a useful solvent for cells?

Its partial charges surround ions and other polar molecules, separating and dispersing them.

Why do functional groups matter in organic molecules?

They give carbon skeletons predictable chemical properties, such as polarity, acidity, or reactivity.

Why can two polymers built from similar monomers have different functions?

Their monomer sequence, branching, length, and three-dimensional shape can differ.

A seedling consumes stored starch. What happens to the starch?

Hydrolysis breaks it into smaller sugars that can enter energy pathways.

What are two biological roles of steroids?

Some act as signaling molecules, and cholesterol helps stabilize animal cell membranes.

What bond forms the backbone of a nucleic-acid strand?

Covalent phosphodiester bonds link the sugar of one nucleotide to the phosphate of the next.

What does denaturation do to a protein?

It disrupts the protein's three-dimensional shape and often its function without usually breaking the primary peptide chain.

An enzyme works best near pH 7 but slows at pH 3. What is a likely explanation?

Extra hydrogen ions changed charges and interactions that maintain the enzyme's active shape.

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.

Автор Open Study Contributor

Изучать эту колоду бесплатно

Откроется Flashcards, и вы сможете начать изучение.

Сведения о колоде

Карточки: 540 карточек
Версия: 1
Опубликовано: 1 сентября 2026 г.
Последнее обновление: 1 сентября 2026 г.
Лицензия: Common knowledge · CC0 1.0
Языки аудитории: en
Теги: ap-bio, ap-bio-u1, ap-bio-u2, ap-bio-u3, ap-bio-u4, ap-bio-u5, ap-bio-u6, ap-bio-u7, ap-bio-u8

Об этой колоде

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

Карточки в этой колоде

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

A colorful biology collage links a cell, DNA helix, energy pathways, inherited variation, and an ecosystem.

540 карточек

AP Biology Flashcards: Complete 8-Unit Course Review

Изучать эту колоду бесплатно

Откроется Flashcards, и вы сможете начать изучение.

Об этой колоде

AP Biology Flashcards: Complete 8-Unit Course Review

What the cards practice

Learning order

What still needs practice

Scope and provenance

Карточки в этой колоде

Карточка 1

Карточка 2

Карточка 3

Карточка 4

Карточка 5

Карточка 6

Карточка 7

Карточка 8

Карточка 9

Карточка 10

Карточка 11

Карточка 12

Карточка 13

Карточка 14

Карточка 15

Карточка 16

Карточка 17

Карточка 18

Карточка 19

Карточка 20

Карточка 21

Карточка 22

Карточка 23

Карточка 24

Карточка 25

Карточка 26

Карточка 27

Карточка 28

Карточка 29

Карточка 30

Карточка 31

Карточка 32

Карточка 33

Карточка 34

Карточка 35

Карточка 36

Карточка 37

Карточка 38

Карточка 39

Карточка 40

Карточка 41

Карточка 42

Карточка 43

Карточка 44

Карточка 45

Карточка 46

Карточка 47

Карточка 48

Карточка 49

Карточка 50

Карточка 51

Карточка 52

Карточка 53

Карточка 54

Карточка 55

Карточка 56

Карточка 57

Карточка 58

Карточка 59

Карточка 60

Карточка 61

Карточка 62

Карточка 63

Карточка 64

Карточка 65

Карточка 66

Карточка 67

Карточка 68

Карточка 69

Карточка 70

Карточка 71

Карточка 72

Карточка 73