Biology Test

Correct Answer: B

Rationale: The correct answer is B, Mitochondrion. Cellular respiration occurs in the mitochondria, where glucose is converted into energy through a series of metabolic processes. Choice A, Golgi apparatus, is incorrect as it is involved in modifying, sorting, and packaging proteins. Choice C, Chloroplast, is incorrect as it is the site of photosynthesis in plant cells, not cellular respiration. Choice D, Ribosome, is incorrect as it is responsible for protein synthesis, not energy production through cellular respiration.

Correct Answer: A

Rationale: Glycolysis, the first step of cellular respiration, takes place in the cytosol and produces two molecules each of ATP, pyruvate, and NADH. Therefore, the correct answer is A. Choice B is incorrect as glycolysis produces two ATP molecules, not four. Choice C is incorrect as it incorrectly states that glycolysis produces four molecules of pyruvate and NADH. Choice D is incorrect because glycolysis produces two molecules of ATP, not four.

Correct Answer: C

Rationale: The correct answer is C: 46. At the start of meiosis, the diploid parent cell contains 46 chromosomes. During meiosis, the number of chromosomes is halved, resulting in each gamete having 23 chromosomes. Choice A (23) is incorrect because that is the number of chromosomes in a human gamete, not the parent cell. Choice B (24) and Choice D (54) are also incorrect as they do not reflect the correct number of chromosomes in a diploid parent cell at the beginning of meiosis.

Correct Answer: C

Rationale: The correct answer is C: Thymine. In DNA, adenine always pairs with thymine, forming a base pair held together by hydrogen bonds. Guanine pairs with cytosine. Uracil is found in RNA, not DNA. Cytosine pairs with guanine. Therefore, option C is the correct pairing for adenine in DNA.

Correct Answer: A

Rationale: The correct answer is A: Cellular respiration. Cellular respiration is the process in cells that converts biochemical energy from nutrients into ATP and releases waste products. This process occurs in the mitochondria of the cell. Choice B, Meiosis, is a type of cell division that produces gametes with half the chromosome number. Choice C, Photosynthesis, is the process by which plants, algae, and some bacteria convert light energy into chemical energy to produce glucose. Choice D, Mitosis, is a type of cell division that results in two daughter cells with identical sets of chromosomes as the parent cell.