Use these biology practice questions to review cell biology, genetics, evolution, ecology, human physiology, enzymes, taxonomy, and experimental design. Work through each question before opening the answer explanation.
Topics Covered
- Cellular respiration and organelles
- Osmosis and membrane transport
- Transcription and gene expression
- Mendelian genetics
- Natural selection
- Energy flow through ecosystems
- Human respiratory physiology
- Enzyme function
- Binomial nomenclature
- Experimental design and variables
Sample Questions
- A. Nucleus
- B. Mitochondrion
- C. Golgi apparatus
- D. Lysosome
Show Answer
Mitochondria carry out major stages of aerobic cellular respiration, including the citric acid cycle and oxidative phosphorylation.
These processes generate most of the ATP produced during aerobic respiration in eukaryotic cells.
- A. Water will move into the cell.
- B. Solute will move into the cell.
- C. Water will move out of the cell.
- D. There will be no net movement of water.
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By osmosis, water moves across a selectively permeable membrane toward the side with the higher effective solute concentration.
Because the surrounding solution is hypertonic relative to the cell, the cell loses water.
- A. Nucleus
- B. Ribosome
- C. Golgi apparatus
- D. Cell membrane
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Transcription uses DNA as a template to produce RNA, and eukaryotic nuclear DNA is located in the nucleus.
Translation occurs later at ribosomes in the cytoplasm or on the rough endoplasmic reticulum.
- A. 0%
- B. 25%
- C. 50%
- D. 100%
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The Tt parent can contribute either T or t, while the tt parent can contribute only t.
The expected offspring are 50% Tt (tall) and 50% tt (short), so 50% are expected to show the recessive phenotype.
- A. Individuals develop useful traits because they need them.
- B. All members of a population change genetically at the same time.
- C. Organisms with heritable traits that improve reproductive success tend to leave more offspring.
- D. Natural selection always produces more complex organisms.
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Natural selection acts on heritable variation in a population.
If a heritable trait increases survival or reproductive success in a particular environment, that trait can become more common across generations.
- A. Energy is destroyed by consumers.
- B. Much of the energy organisms obtain is used in metabolism and released as heat.
- C. Producers receive no energy from sunlight.
- D. Predators cannot store chemical energy.
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Only part of the energy taken in at one trophic level becomes biomass available to the next level.
Organisms use much of their energy for metabolism, movement, maintenance, and other processes, with substantial energy ultimately dissipated as heat.
- A. Trachea
- B. Bronchi
- C. Alveoli
- D. Diaphragm
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Alveoli are tiny air sacs surrounded by capillaries.
Their thin walls and large combined surface area allow oxygen and carbon dioxide to diffuse efficiently between air and blood.
- A. It lowers the activation energy required for the reaction.
- B. It changes the reaction’s final equilibrium position.
- C. It permanently becomes part of the product.
- D. It supplies all of the energy needed by the reactants.
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Enzymes are biological catalysts that increase reaction rates by providing a pathway with a lower activation energy.
They do not change the reaction’s overall equilibrium and are not permanently consumed by the reaction.
- A. Family
- B. Genus
- C. Specific epithet
- D. Order
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In binomial nomenclature, the first word is the genus and the second word is the specific epithet.
Together, Homo sapiens forms the species name.
- A. The final height of each plant
- B. The concentration of fertilizer applied
- C. The number of leaves produced
- D. The average height calculated after the experiment
Show Answer
The independent variable is the factor deliberately changed by the researcher.
Plant height is the dependent variable because it is the measured outcome expected to respond to the fertilizer treatment.
How to Use These Questions
For each question, identify the biological level being tested: molecular, cellular, organismal, population, or ecosystem. That can help eliminate answers that describe a real biological concept but at the wrong level.
For genetics and experimental-design questions, write out the relevant relationship before choosing an answer. For processes such as osmosis, natural selection, and energy flow, focus on the direction of change rather than memorizing isolated vocabulary.