HESI A2 Biology Practice Test

Correct Answer: A

Rationale: The correct answer is A: fat-soluble hormones. Fat-soluble hormones can diffuse through the cell membrane due to their lipophilic nature. Once inside the cell, they can bind to receptors located in the cytoplasm or nucleus to initiate a chemical response. This process allows fat-soluble hormones to directly affect gene expression and protein synthesis within the target cell. In contrast, choices B, C, and D (amino acid derivatives, hydrophilic, and water-soluble hormones) cannot diffuse through the cell membrane and typically bind to receptors on the cell surface to trigger a signaling cascade.

Correct Answer: B

Rationale: The correct answer is B: Prokaryotic cells have a capsule. This is because the capsule is a protective layer outside the cell wall that helps the prokaryotic cell adhere to surfaces and evade the immune system. Prokaryotic cells do not have a nucleus (choice A), membrane-bound organelles (choice C), or the ability to move on their own (choice D). The absence of a nucleus and membrane-bound organelles distinguishes prokaryotic cells from eukaryotic cells. Choice D is incorrect because prokaryotic cells can move using various mechanisms such as flagella or pili.

Correct Answer: D

Rationale: The correct answer is D: cellular respiration and fermentation. Cellular respiration is the process by which cells convert glucose and oxygen into ATP, providing energy for the cell. Fermentation is an anaerobic process that also produces ATP but does not require oxygen. Both pathways are catabolic, breaking down molecules to release energy. Option A is incorrect because protein synthesis is an anabolic process that builds proteins and does not directly produce energy. Option B is incorrect because cellular respiration and glycolysis are both energy-producing pathways, not protein synthesis. Option C is incorrect because it includes fermentation and glycolysis, omitting cellular respiration, which is a major pathway for energy production in cells.

Correct Answer: D

Rationale: The correct answer is D: Biomes. Biomes are large geographical areas characterized by specific climate, vegetation, and animal life. Tundra, savannas, grasslands, deserts, and rainforests are all examples of biomes. They are classified based on factors like temperature, precipitation, and flora/fauna. Biomasses (A) refer to the total mass of living organisms in a given area. Biospheres (B) are the regions of the Earth where life exists. Biodiversity (C) refers to the variety and variability of life forms in a specific habitat, not the specific types of habitats themselves.

Correct Answer: D

Rationale: The correct answer is D because all the choices - the pituitary gland, the thyroid gland, and the adrenal glands - are indeed components of the endocrine system. Each of these glands secretes hormones directly into the bloodstream to regulate various bodily functions. The pituitary gland controls other endocrine glands, the thyroid gland regulates metabolism, and the adrenal glands manage stress responses. Therefore, all of these glands play vital roles in the endocrine system. The other choices (A, B, C) are incorrect because they are all components of the endocrine system.