HESI A2 Biology 2024

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: A

Rationale: The correct answer is A. When messenger RNA reaches the cytoplasm, it attaches to a ribosome for protein synthesis. Ribosomes are the cellular machinery responsible for translating the genetic code carried by mRNA into proteins. Option B is incorrect as mRNA does not "unzip" in the cytoplasm. Option C is incorrect because mRNA does not pair with DNA bases in the cytoplasm; it pairs with ribosomes. Option D is incorrect as mRNA does not "pull free" of the DNA strand in the cytoplasm; it has already been transcribed from DNA in the nucleus.

Correct Answer: C

Rationale: The correct answer is C (50%). In this scenario, the male offspring will inherit the X chromosome with the hemophilia gene from the mother, making him a hemophiliac. The female offspring will inherit one X chromosome with the hemophilia gene, making her a carrier. Therefore, 50% of the offspring are predicted to be carriers only. Option A (0%) is incorrect as carriers will be present. Option B (25%) is incorrect because only male offspring will have hemophilia. Option D (100%) is incorrect as not all offspring will be carriers.

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: A

Rationale: The correct answer is A: Blue. Blue light is essential for photosynthesis as it is absorbed by chlorophyll, the pigment that drives the process. Blue light helps in vegetative growth and overall plant development. Yellow, green, and orange lights are not as effective as they are not as readily absorbed by plants for photosynthesis. Yellow and green lights do not provide the necessary energy for plant growth, while orange light is less efficient in promoting photosynthesis compared to blue light. Therefore, blue light is the most effective choice for growing green plants indoors.