Biology HESI A2 2024

Correct Answer: C

Rationale: The purpose of phloem tissue in plant stems is to conduct food throughout the plant. Phloem is responsible for transporting sugars, amino acids, and other organic compounds produced through photosynthesis from the leaves to other parts of the plant for growth and energy. This process is known as translocation. Choice A is incorrect because water is transported by xylem tissue, not phloem. Choice B is incorrect as phloem does not conduct light energy. Choice D is incorrect as carbon dioxide is absorbed by the plant through stomata and transported through the plant via diffusion, not through phloem tissue.

Correct Answer: B

Rationale: To determine the percentage of offspring that are carriers but not manifesting the disease, we need to consider the Punnett square. When both parents carry the recessive gene, there is a 25% chance of producing homozygous recessive offspring with cystic fibrosis. This means the remaining 75% will be carriers (heterozygous) but not show symptoms. Therefore, the correct answer is B (25%). A: 0% - Incorrect, as carriers are present. C: 50% - Incorrect, as it does not account for the probability of being a carrier. D: 100% - Incorrect, as not all offspring will manifest the disease.

Correct Answer: D

Rationale: The correct answer is D: Salmonella. Binary fission is a form of asexual reproduction where a single organism divides into two identical organisms. Salmonella is a bacterium that reproduces through binary fission. Mushrooms reproduce via spores, blue whales and rainbow trout reproduce sexually. Therefore, Salmonella is the only organism among the choices that reproduces via binary fission.

Correct Answer: D

Rationale: In a lysosome, enzymes break down food particles through the process of digestion. This process helps to recycle nutrients and eliminate waste materials. Ribosomes are not made in lysosomes, as they are responsible for protein synthesis. Lysosomes do not produce food but rather break it down. Water storage does not occur in lysosomes. Therefore, the correct answer is D - food is digested in a lysosome.

Correct Answer: B

Rationale: During interphase, the cell prepares for division by replicating its DNA, including the chromosomes. This occurs before the actual cell division stages of mitosis or meiosis. Prophase is the stage where chromosomes condense, not replicate. Anaphase is when sister chromatids separate, and telophase is the final stage where chromosomes de-condense. Therefore, the correct answer is B (Interphase) as it is the specific phase where chromosome replication occurs.