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: A

Rationale: The correct answer is A: DNA replication, mitosis, and cytokinesis. In the haploid cell cycle, DNA replication occurs during the S phase, followed by mitosis where the duplicated chromosomes are separated into two daughter cells, and finally, cytokinesis completes the division of the cytoplasm. Choice B is incorrect because meiosis is a process specific to the diploid cell cycle, not the haploid cell cycle. Choice C is incorrect as degradation is not a main event in the cell cycle. Choice D is incorrect because apoptosis is a programmed cell death process and not a regular event in the cell cycle.

Correct Answer: A

Rationale: Enzymes can catalyze reactions by lowering the activation energy required for the reaction to occur, thus increasing the reaction rate. This is achieved through the formation of enzyme-substrate complexes. Inhibition refers to the process of preventing enzyme activity, which is contrary to the function of enzymes. Stopping reactions is not the role of enzymes. Therefore, the correct answer is A: Catalyze.

Correct Answer: C

Rationale: The correct answer is C: Tight junctions. Tight junctions are specialized connections between cells that form a barrier to prevent leakage of substances between cells. They are important for maintaining the integrity and function of epithelial and endothelial tissue. Separate desmosomes (choice A) are incorrect because desmosomes are anchoring junctions, not tight junctions. Ronofilaments (choice B) is not a term related to cell junctions. Fascia adherens (choice D) is incorrect as it refers to a type of adherens junction, not tight junctions.

Correct Answer: D

Rationale: The correct answer is D, the endocrine system. This system releases hormones directly into the bloodstream to regulate various bodily functions and maintain homeostasis. Hormones act as chemical messengers that travel throughout the body to target cells or organs, influencing processes like metabolism, growth, and mood. The gastrointestinal system (choice A) primarily focuses on digestion and nutrient absorption, not hormone release. The digestive system (choice C) is responsible for breaking down food and absorbing nutrients, not hormone regulation. The repetition of the endocrine system as choice D is likely a mistake.