HESI A2 Biology 2024

Correct Answer: A

Rationale: The correct answer is A: Red cedar. Gymnosperms are a group of seed-producing plants that do not have enclosed seeds. Red cedar is a gymnosperm because it produces naked seeds that are not enclosed in a fruit or ovary. Japanese cherry (B), Flowering dogwood (C), and American chestnut (D) are examples of angiosperms, which are seed-producing plants with enclosed seeds within a fruit or ovary. Therefore, they are not examples of gymnosperms.

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: Rationale: 1. The Krebs cycle produces ATP (A), CO2 (B), and NADH (D) as products. 2. Glucose (C) is not directly produced by the Krebs cycle; glucose is the starting molecule that enters glycolysis before the Krebs cycle. Summary: A, B, and D are products of the Krebs cycle, while glucose (C) is not directly produced by the Krebs cycle but is a substrate for glycolysis.

Correct Answer: A

Rationale: The correct answer is A: Hydrogen atoms. Saturated fats have all of their carbon atoms bonded to hydrogen atoms, with no double bonds between carbon atoms. This results in a "saturated" molecule with as many hydrogen atoms as possible. Choices B, C, and D are incorrect because saturated fats are not saturated with carbon, oxygen, or nitrogen atoms. These choices do not accurately reflect the chemical structure of saturated fats, which are primarily composed of carbon and hydrogen atoms.

Correct Answer: B

Rationale: The correct answer is B: Vacuole. Vacuoles are organelles that provide storage space for the cell, storing water, nutrients, and waste products. They help maintain the cell's internal pressure and shape. Mitochondria (A) are responsible for energy production, not storage. The cell membrane (C) is a protective barrier, and ribosomes (D) are involved in protein synthesis, not storage. Therefore, only the vacuole fits the role of providing storage space for the cell.