HESI A2 Biology 2024

Correct Answer: A

Rationale: Hydrolysis is the correct term for the breakdown of glycogen into glucose subunits. During hydrolysis, a water molecule is used to break the bonds between glucose molecules in glycogen, resulting in the release of individual glucose units. This process is catalyzed by enzymes like glycogen phosphorylase. Reduction is the gain of electrons, not relevant here. Metabolism is a broad term encompassing all chemical reactions in the body, not specific to glycogen breakdown. Transpiration is the loss of water vapor from plants, not related to the breakdown of glycogen.

Correct Answer: D

Rationale: To facilitate active transport through a membrane, ATP (adenosine triphosphate) is necessary. ATP provides the energy required for active transport processes to move molecules against their concentration gradient. Glucose (Choice A) and Sodium (Choice C) are often transported through active transport mechanisms, but they are not the energy source themselves. Oxygen (Choice B) is typically transported through passive diffusion due to its small size. Therefore, the correct answer is D (ATP) as it directly supplies the energy needed for active transport to occur.

Correct Answer: D

Rationale: The correct answer is D: Decomposer. Decomposers have the greatest energy efficiency among the given choices because they obtain energy by breaking down organic matter into simpler substances. This process requires less energy compared to the consumption and digestion processes in herbivores, carnivores, and omnivores. Decomposers play a vital role in recycling nutrients in ecosystems. Herbivores, carnivores, and omnivores have lower energy efficiency as they need to expend energy in hunting, digesting, and metabolizing food sources.

Correct Answer: C

Rationale: The correct answer is C because counting birds at the same feeder at two different times (noon and 6:00 P.M.) provides a more accurate representation of bird activity throughout the day. This method allows the student to observe any variations in bird populations at different times, capturing potential fluctuations in activity levels. Choice A (counting birds at one feeder every 6 hours) may miss out on important changes in bird presence during different times of the day. Choice B (counting birds at three feeders at noon and 6:00 P.M.) increases the complexity and potential for errors in data collection. Choice D (counting birds at three feeders every 6 hours) may lead to redundancy and a lack of focus on specific feeding areas.

Correct Answer: B

Rationale: The correct answer is B: Green. Chlorophyll, the pigment responsible for photosynthesis, absorbs light most efficiently in the red and blue regions of the spectrum. Green light is reflected, making it least effective. Violet, orange, and red lights are more readily absorbed by chlorophyll, enhancing photosynthesis. This is due to the specific absorption spectrum of chlorophyll, where green light is least absorbed.