Nursing Elites

1. In meiosis, the chromosome number is reduced from:

• A. 46 to 23
• B. 46 to 33
• C. 28 to 14
• D. 24 to 12

Correct answer: A

Rationale: The correct answer is A: "46 to 23." In meiosis, the chromosome number is reduced by half to form gametes for sexual reproduction. In humans, where the diploid chromosome number is 46, meiosis results in haploid cells with 23 chromosomes. Choices B, C, and D are incorrect because they do not represent the correct reduction in chromosome number during meiosis.

2. Prophase is the first stage of mitosis. Which of the following best describes chromosomes during this stage?

• A. They are gathered on either side of the separating cell
• B. They are all aligned along the metaphase plate
• C. They are attached to the spindle
• D. They are visibly separate

Correct answer: D

Rationale: The correct answer is D. During prophase, the chromosomes condense and become visible as distinct structures under a microscope. Choice A is incorrect as chromosomes are not gathered on either side of the separating cell during prophase. Choice B is incorrect because chromosomes align along the metaphase plate during the subsequent stage, metaphase. Choice C is incorrect as chromosomes become attached to the spindle fibers during prometaphase, the stage following prophase.

3. Why does ice have the capability of floating on water?

• A. It has a higher viscosity
• B. It has a different chemical composition
• C. It has a high specific heat
• D. It forms a lattice when freezing

Correct answer: D

Rationale: The correct answer is D. Ice forms a lattice structure when it freezes, which makes it less dense than liquid water, allowing it to float. Choice A is incorrect because viscosity refers to a fluid's resistance to flow and is not related to ice floating. Choice B is incorrect as ice and liquid water have the same chemical composition (H2O). Choice C is incorrect because the high specific heat of water is not the reason why ice floats.

4. Which of the following is a lipid that is a membrane component and a precursor to significant hormones?

• A. Nucleic acids
• B. Proteins
• C. Carbohydrates
• D. Steroids

Correct answer: D

Rationale: The correct answer is D, Steroids. Steroids are a type of lipid that function as essential components of cell membranes and serve as precursors for significant hormones like estrogen and testosterone. Nucleic acids (choice A) are not lipids but are molecules like DNA and RNA that store genetic information. Proteins (choice B) and carbohydrates (choice C) are biomolecules but are not lipids and do not serve as precursors for hormones or membrane components.

5. Which of the following processes produces nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FADH2) for the electron transport chain during cellular respiration?

• A. Electron transport chain
• B. Glycolysis
• C. Citric acid cycle (the Krebs cycle)
• D. None of these

Correct answer: C

Rationale: The correct answer is C, the citric acid cycle (the Krebs cycle). This cycle generates NADH and FADH2, which play a crucial role in providing electrons to the electron transport chain during cellular respiration. Choice A, the electron transport chain itself, is where NADH and FADH2 donate their electrons, not where they are produced. Choice B, glycolysis, produces NADH but not FADH2. Choice D, 'None of these,' is incorrect as the citric acid cycle specifically produces NADH and FADH2.

Similar Questions