Biology Practice Test

Correct Answer: B

Rationale: The correct answer is B, Telophase. During telophase, the chromosomes gather at opposite poles of the cell as the nuclear envelopes start to form around them, indicating the end of cell division. Choices A, C, and D are incorrect because during metaphase, the chromosomes align in the middle of the cell; in anaphase, the chromosomes separate and move towards opposite poles; and in prophase, the chromosomes condense and the nuclear envelope breaks down, respectively.

Correct Answer: A

Rationale: The correct answer is A: Nucleic acids. DNA and RNA are both types of nucleic acids, which are fundamental biological molecules responsible for storing and transmitting genetic information. Choice B, Proteins, are not subunits of DNA and RNA but are composed of amino acids. Carbohydrates, choice C, are another type of biological molecule involved in energy storage and structural support, not subunits of DNA and RNA. Lipids, choice D, are a diverse group of molecules that include fats, oils, and steroids, but they are not subunits of DNA and RNA.

Correct Answer: D

Rationale: The rough endoplasmic reticulum is studded with ribosomes, which are responsible for protein synthesis. Ribosomes are the correct answer because they are the organelles directly associated with the rough endoplasmic reticulum. Microvilli (choice A), mitochondria (choice B), and lysosomes (choice C) are not typically located on the rough endoplasmic reticulum. Microvilli are found on the surface of cells to increase surface area, mitochondria are the powerhouses of the cell responsible for energy production, and lysosomes are membrane-bound organelles containing digestive enzymes.

Correct Answer: A

Rationale: The electron transport chain is the step in cellular respiration that generates the most ATP. During this step, up to 34 ATP molecules can be produced from a single glucose molecule. Choice B, Glycolysis, produces a smaller amount of ATP (2 ATP molecules per glucose), and choice C, Citric acid cycle, produces some ATP but not as much as the electron transport chain. Choice D is incorrect because different steps of cellular respiration produce varying amounts of ATP, with the electron transport chain being the most efficient in ATP generation.

Correct Answer: D

Rationale: The rough endoplasmic reticulum is studded with ribosomes, not microvilli, mitochondria, or lysosomes. Ribosomes are responsible for protein synthesis, making them an essential component of the rough endoplasmic reticulum.