HESI A2 Biology 2024

Correct Answer: C

Rationale: The correct answer is C: Order. Classification starts from the broadest category (Kingdom) to the most specific (Genus). Carnivora is an Order in the classification hierarchy, encompassing various families of carnivorous mammals, including dogs. Therefore, the correct classification for dogs within the Carnivora group is Order. Choices A, B, and D are incorrect because Kingdom refers to the highest taxonomic rank, Class is a level below Order, and Genus is a more specific category than Order.

Correct Answer: B

Rationale: The correct answer is B: Amino acids bond. In the final step of protein synthesis, amino acids bond together to form a polypeptide chain. This process occurs on the ribosomes, where transfer RNA delivers the specific amino acids according to the codons on the messenger RNA. DNA unzipping (A) happens during transcription, while transfer RNA bonding to messenger RNA (C) is part of the initiation step of translation. Messenger RNA moving to ribosomes (D) is essential for protein synthesis but is not the final step where amino acids bond.

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: D

Rationale: The correct answer is D: Mitosis. In the tip of a plant's root, cells undergo mitosis to increase in number. In mitosis, a parent cell divides into two identical daughter cells, ensuring the growth and repair of tissues. Meiosis, choice A, is a process of cell division that produces gametes with half the genetic material. Cytokinesis, choice B, is the process of cytoplasmic division following cell division. Fractioning, choice C, is not a biological process related to cell division. Mitosis is the only process mentioned that specifically describes cell division for growth and repair in plants.

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.