HESI A2 Biology Practice Test

Correct Answer: B

Rationale: The correct answer is B: Create energy. Mitochondria are known as the powerhouse of the cell because they produce ATP, the primary energy source for cellular functions. They do this through a process called cellular respiration. Option A is incorrect as the nucleus controls the cell. Option C is incorrect as protein synthesis occurs in the ribosomes. Option D is incorrect as waste packaging is typically done by lysosomes.

Correct Answer: A

Rationale: The correct answer is A because water is a raw material for the light reactions in photosynthesis, specifically in the process of photolysis where water is split to release electrons for the photosystems. Without enough water, this process is hindered, leading to a drop in photosynthetic rate. Choice B is incorrect because carbon dioxide availability affects the Calvin cycle, not the light reactions. Choice C is incorrect as carbon atoms for sugar come from carbon dioxide, not water. Choice D is incorrect because fermentation is not directly related to the availability of water in photosynthesis.

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: B

Rationale: To focus an image using a compound microscope, adjusting the fine adjustment is correct as it allows for precise focusing when switching magnifications. Coarse adjustment is only used initially to bring the specimen into view, while the stage adjustment is used to center the specimen. Therefore, B is correct as it ensures clear and sharp image focus without unnecessary readjustments. Choices A and C are incorrect as they do not address the specific need for precise focusing when changing magnifications, leading to potential blurriness or loss of focus in the image.

Correct Answer: B

Rationale: The correct answer is B because of osmosis. Saltwater has a higher concentration of solute than the egg, causing water to move out of the egg, leading to shrinkage. A is incorrect as the egg will lose water, not expand. C is incorrect as there will be a change due to osmosis. D is incorrect as an effect will occur.