HESI A2
Biology HESI A2 2024
1. What is represented by this formula: 6COâ‚‚ + 6Hâ‚‚O → C₆Hâ‚â‚‚O₆ + 6Oâ‚‚?
- A. Glycolysis
- B. Cellular respiration
- C. Photosynthesis
- D. Electronic transport
Correct answer: C
Rationale: The formula represents the process of photosynthesis, where carbon dioxide (COâ‚‚) and water (Hâ‚‚O) are converted into glucose (C₆Hâ‚â‚‚O₆) and oxygen (Oâ‚‚) using light energy. This process is essential for plants and some microorganisms to produce food and oxygen. Glycolysis and cellular respiration involve breaking down glucose to produce energy, and the electron transport chain is part of cellular respiration, not photosynthesis.
2. Which organelle is responsible for organizing protein synthesis?
- A. Nucleus
- B. Ribosome
- C. Lysosome
- D. Vacuole
Correct answer: B
Rationale: The correct answer is B: Ribosome. Ribosomes are responsible for organizing protein synthesis by assembling amino acids. They are the cellular machinery where proteins are synthesized. The other choices, such as the nucleus, lysosome, and vacuole, do not directly participate in protein synthesis. The nucleus contains DNA and controls cell activities, the lysosome is involved in digestion and waste removal, and the vacuole is responsible for storage and maintaining cell turgor pressure.
3. Which of the following is true of Glycolysis?
- A. It requires the absence of Oxygen
- B. It occurs in the presence of Oxygen
- C. It is the final step of fermentation
- D. It is the final step of anaerobic respiration
Correct answer: B
Rationale: Glycolysis is the first step in cellular respiration and can occur in both aerobic (presence of oxygen) and anaerobic (absence of oxygen) conditions. In aerobic respiration, glycolysis takes place in the presence of oxygen and continues with the Krebs cycle and the electron transport chain. So, glycolysis does not require the absence of oxygen but can occur in its presence as part of the overall process of aerobic respiration. Choice A is incorrect because glycolysis can occur in the presence of oxygen. Choice C is incorrect because glycolysis is not the final step of fermentation; it is the initial step. Choice D is incorrect because glycolysis is not the final step of anaerobic respiration; it is the first step, followed by further processes to complete anaerobic respiration.
4. What is the function of water in photosynthesis?
- A. Combine with carbon dioxide
- B. Absorb light energy
- C. Supply electrons in the light reactions
- D. Transport hydrogen ions in the dark reactions
Correct answer: C
Rationale: The correct answer is C: 'Supply electrons in the light reactions.' In photosynthesis, water is split during the light reactions of photosynthesis, releasing electrons that are used in the formation of ATP and NADPH, crucial for the synthesis of glucose. Choice A is incorrect because water does not combine with carbon dioxide in photosynthesis. Choice B is incorrect as water does not absorb light energy directly. Choice D is incorrect because the transportation of hydrogen ions mainly occurs in the electron transport chain, which is part of the light reactions, not the dark reactions.
5. How many chromosomes do sperm and egg produce in meiosis?
- A. 23
- B. 46
- C. 25
- D. 50
Correct answer: A
Rationale: During meiosis, sperm and egg cells produce half the number of chromosomes found in somatic cells. Each contributes 23 chromosomes, which combine to form a zygote with a total of 46 chromosomes. Choice B (46) is incorrect because this is the number of chromosomes produced in mitosis, not meiosis. Choices C (25) and D (50) are also incorrect as they do not align with the chromosome count in sex cells during meiosis.
Similar Questions
Access More Features
HESI A2 Basic
$49/ 30 days
- 3,000 Questions with answers
- 30 days access
HESI A2 Premium
$99/ 90 days
- Actual HESI A2 Questions
- 3,000 questions with answers
- 90 days access