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