HESI A2 Biology Practice Test

Correct Answer: D

Rationale: Failed to generate a rationale after 5 retries.

Correct Answer: D

Rationale: The correct answer is D because mitosis is essential for the growth and repair of body tissues. During mitosis, a cell divides to produce two identical daughter cells with the same genetic information as the parent cell. This process is crucial for replacing damaged or dead cells, allowing for growth and tissue repair. A is incorrect because mitosis does not involve the fusion of male and female gametes, which is a process called fertilization. B is incorrect because mitosis actually maintains genetic consistency within a species by producing genetically identical cells. C is incorrect because mitosis typically produces cells that are very similar to the parent cell, ensuring the preservation of genetic information and function.

Correct Answer: C

Rationale: Anaerobic respiration occurs in bacteria because they live in environments with low oxygen levels. Bacteria adapt to anaerobic conditions by utilizing alternative pathways to generate energy without oxygen. This process allows them to survive and thrive in oxygen-deprived environments. The other choices are incorrect because animals require oxygen for aerobic respiration, plants use sunlight for photosynthesis, and option D is incorrect as bacteria indeed undergo anaerobic respiration in low oxygen environments.

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: D

Rationale: The plasma membrane is a phospholipid bilayer, meaning it consists of two layers of phospholipid molecules. This arrangement forms a barrier that separates the cell from its external environment. The hydrophobic tails of the phospholipids face inward, while the hydrophilic heads face outward. This structure allows the membrane to control the movement of substances in and out of the cell. Choices A and B are incorrect as the membrane is not solely made of proteins. Choice C is incorrect as the membrane consists of a double layer of phospholipids, not a single layer.