Biology HESI A2 2024

Correct Answer: D

Rationale: The correct answer is D: Carbohydrates. Glucose is a type of simple sugar and a carbohydrate. Carbohydrates are composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio, which is the molecular formula of glucose (C6H12O6). Proteins (choice A) are composed of amino acids, lipids (choice B) are composed of fatty acids and glycerol, and nucleic acids (choice C) are composed of nucleotides. Therefore, only carbohydrates, specifically glucose, contain the specific molecular structure that characterizes glucose.

Correct Answer: B

Rationale: The correct answer is B: Both are prokaryotes. Rationale: 1. Bacteria and blue-green algae lack a true nucleus, membrane-bound organelles, and have a simpler cellular structure, indicating they are prokaryotes. 2. Prokaryotes are distinct from eukaryotes, which have a true nucleus and membrane-bound organelles. 3. Gymnosperms (choice A) are seed-producing plants, not related to bacteria or blue-green algae. 4. Autotrophs (choice C) can include plants, algae, and some bacteria, but not all bacteria are autotrophs. 5. Pathogens (choice D) are disease-causing agents, not a characteristic that defines the classification of bacteria and blue-green algae.

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: 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: D

Rationale: Correct Answer: D - DNA cannot be altered. Rationale: 1. DNA can be altered through mutations, recombination, and other genetic processes. 2. DNA repair mechanisms exist to correct alterations. 3. Alterations in DNA are essential for evolution and genetic diversity. Summary: A: True - RNA is single-stranded. B: True - RNA contains uracil. C: True - DNA codes for proteins.