Biology HESI A2 Practice Test

Correct Answer: C

Rationale: The correct answer is C: epididymis. The epididymis is the structure in the male reproductive system that stores spermatozoa during the maturation process. Sperm are produced in the testes and then move to the epididymis for storage and maturation before being ejaculated. The vas deferens is the tube that carries mature sperm from the epididymis to the urethra during ejaculation. The scrotum is the external sac that holds the testes and helps regulate their temperature. The testicular artery supplies blood to the testes but is not directly involved in storing spermatozoa.

Correct Answer: B

Rationale: Cytosine and thymine are pyrimidines because they are smaller, single-ring nitrogenous bases found in DNA and RNA. Purines have a double-ring structure, which includes adenine and guanine. Choice A is incorrect because purines have a different structure. Choice C is incorrect because cytosine and thymine are specifically pyrimidines, not both. Choice D is incorrect as they are classified as pyrimidines.

Correct Answer: C

Rationale: The correct answer is C: Cells can convert nutrients to energy. Cellular respiration is the process by which cells break down nutrients to produce energy in the form of ATP. This energy is essential for various cellular functions. Choice A is incorrect because DNA replication is a separate process. Choice B is incorrect as cellular respiration is not related to breathing, which is the exchange of gases. Choice D is incorrect as cell division is a different cellular process called mitosis or meiosis.

Correct Answer: C

Rationale: The correct answer is C: prokaryotic. Prokaryotic cells lack membrane-bound organelles and a defined nucleus. They have a simple structure with genetic material floating freely in the cytoplasm. Eukaryotic cells (choice A) have membrane-bound organelles and a nucleus. Embryonic (choice B) refers to a developmental stage, not a cell classification. Symbiotic (choice D) relates to a mutually beneficial relationship between two organisms, not cell classification. In summary, prokaryotic cells are characterized by their lack of membrane-bound organelles and nucleus, distinguishing them from eukaryotic cells, embryonic stages, and symbiotic relationships.

Correct Answer: C

Rationale: The correct answer is C (bb) because tan fur is the recessive phenotype controlled by the tan allele (b). Since the black allele (B) exhibits complete dominance, a dog must have two copies of the tan allele (bb) to have a tan fur phenotype. Choice A (BB) and B (Bb) would result in black fur, not tan. Choice D (Not enough information) is incorrect as the question provides enough information to determine the correct genotype based on the phenotype given.