Biology HESI A2 2024

Correct Answer: D

Rationale: The correct answer is D: Carbohydrates. Glucose is a type of simple sugar and a carbohydrate. Carbohydrates are composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio, which is the molecular formula of glucose (C6H12O6). Proteins (choice A) are composed of amino acids, lipids (choice B) are composed of fatty acids and glycerol, and nucleic acids (choice C) are composed of nucleotides. Therefore, only carbohydrates, specifically glucose, contain the specific molecular structure that characterizes glucose.

Correct Answer: C

Rationale: The formula represents the process of photosynthesis where carbon dioxide (CO₂) and water (H₂O) are converted into glucose (C₆H₁₂O₆) and oxygen (O₂) in the presence of sunlight. Step 1: 6CO₂ + 6H₂O represent the reactants involved in photosynthesis. Step 2: C₆H₁₂O₆ + 6O₂ represent the products formed during photosynthesis. Therefore, the correct answer is C: Photosynthesis. Other choices are incorrect because: A: Glycolysis involves the breakdown of glucose into pyruvate. B: Cellular respiration involves the breakdown of glucose to produce energy. D: Electronic transport is related to the movement of electrons in cellular respiration, not photosynthesis.

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: 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: 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.