Biology HESI A2 2024

Correct Answer: A

Rationale: The correct answer is A: Stamen. The stamen is the male reproductive organ of a flower, producing pollen containing male gametes. The pistil, stigma, and style are all parts of the female reproductive system, involved in receiving pollen and supporting the development of seeds. Therefore, the stamen is of a different "gender" than the others, making it the correct choice. Stigma and style are specifically part of the pistil, which is the female organ of the flower.

Correct Answer: C

Rationale: The correct answer is C: Nitrification. The water cycle includes evaporation, condensation, precipitation, and collection. Nitrification is a process in the nitrogen cycle, not the water cycle. Condensation is the conversion of water vapor into liquid water. Transpiration is the release of water vapor from plants. Absorption refers to water being taken up by plants or soil. Nitrification, the process of converting ammonia into nitrates, is unrelated to the movement of water in the water cycle.

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: B

Rationale: The correct answer is B: Parasitism. In parasitism, one organism benefits (the pneumonia bacterium) at the expense of the other (the human). The bacterium causes harm to the human by causing pneumonia, which is detrimental. In mutualism (A), both organisms benefit; in commensalism (C), one benefits while the other is unaffected; in competition (D), both organisms are harmed by vying for the same resources. Hence, parasitism is the most fitting description of the relationship between the pneumonia bacterium and the human in this scenario.

Correct Answer: A

Rationale: The correct answer is A: Stamen. The stamen is the male reproductive organ of a flower, producing pollen containing male gametes. The pistil, stigma, and style are all parts of the female reproductive system, involved in receiving pollen and supporting the development of seeds. Therefore, the stamen is of a different "gender" than the others, making it the correct choice. Stigma and style are specifically part of the pistil, which is the female organ of the flower.