Biology HESI A2 2024

Correct Answer: A

Rationale: The correct answer is A: It will swell and possibly burst. This is because the solution outside the cell is hypotonic compared to the inside, causing water to move into the cell through osmosis, leading to swelling. If the influx of water is excessive, the cell may burst. Explanation for other choices: B: It will shrivel and shrink - This would happen if the solution outside the cell is hypertonic, causing water to move out of the cell, leading to shrinkage. C: It will maintain its current size - In an isotonic solution, there would be no net movement of water, so the cell would maintain its size. D: It will grow a supportive cell wall - Cell walls are typically found in plant cells and serve different functions. The growth of a cell wall is not directly related to the concentration of solutes inside and outside the cell.

Correct Answer: C

Rationale: The purpose of phloem tissue in plant stems is to conduct food throughout the plant. Phloem is responsible for transporting sugars, amino acids, and other organic compounds produced through photosynthesis from the leaves to other parts of the plant for growth and energy. This process is known as translocation. Choice A is incorrect because water is transported by xylem tissue, not phloem. Choice B is incorrect as phloem does not conduct light energy. Choice D is incorrect as carbon dioxide is absorbed by the plant through stomata and transported through the plant via diffusion, not through phloem tissue.

Correct Answer: B

Rationale: The correct answer is B because it involves a controlled experiment with two distinct groups - one exposed to chocolate and the other not. This allows for comparison to determine the impact of chocolate consumption on acne. Option A lacks a control group for comparison. Option C only uses one participant, which is not enough to draw generalizable conclusions. Option D does not have a control group and the order of exposure is reversed, which may affect the results. In summary, choice B is the most appropriate as it includes a control group, clear exposure to the variable of interest, and enables comparison between the two groups.

Correct Answer: C

Rationale: The correct answer is C because yeast carries out fermentation, producing ethanol and carbon dioxide. During fermentation, yeast breaks down sugars in the dough into ethanol and carbon dioxide gas. The carbon dioxide gas gets trapped in the dough, causing it to rise. Choice A is incorrect because yeast does not engage in photosynthesis. Choice B is incorrect because yeast does not carry out photosynthesis at all. Choice D is incorrect because yeast primarily produces carbon dioxide through fermentation, not aerobic respiration.

Correct Answer: B

Rationale: The correct answer is B: Parasitism. In parasitism, one organism benefits (the pneumonia bacterium) at the expense of the other (the human). The bacterium causes harm to the human by causing pneumonia, which is detrimental. In mutualism (A), both organisms benefit; in commensalism (C), one benefits while the other is unaffected; in competition (D), both organisms are harmed by vying for the same resources. Hence, parasitism is the most fitting description of the relationship between the pneumonia bacterium and the human in this scenario.