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: B

Rationale: The correct answer is B: shape. Enzyme activity is highly dependent on the enzyme's specific three-dimensional shape. Changes in temperature and pH can disrupt the hydrogen bonds and other interactions that maintain the enzyme's shape, leading to denaturation. This alters the active site of the enzyme, making it unable to bind effectively with its substrate and catalyze the reaction. Incorrect options: A: Acidity is related to pH, which can affect enzyme activity, but the primary reason for the alteration is the change in shape. C: While changes in pH can affect the chemical properties of enzymes, the main impact on enzyme activity is the alteration of shape. D: Substrate is the molecule upon which the enzyme acts, and while changes in substrate concentration can affect enzyme activity, alterations in temperature and pH primarily impact the enzyme's shape, not the substrate itself.

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: 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: D

Rationale: The correct answer is D: genus; species. "Felis" is the genus and "catus" is the species in the scientific name Felis catus. Genus is a broader classification that includes closely related species, while species is the most specific classification level. Kingdom (choice A) is too broad, family (choice A) is at a higher level than species, order (choice B) is too specific, subspecies (choice B) is not part of the scientific name, phylum (choice C) is too broad, and class (choice C) is a higher classification level than species.