Nursing Elites

1. 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.

2. What is the difference between DNA and RNA?

• A. RNA has an extra Phosphate group
• B. DNA has one less oxygen than RNA
• C. RNA has one less oxygen than DNA
• D. DNA has an extra sugar molecule

Correct answer: B

Rationale: The correct answer is B. DNA has one less oxygen atom in its sugar molecule (deoxyribose) compared to RNA, which has a ribose sugar. Choice A is incorrect because RNA does not have an extra phosphate group. Choice C is incorrect as RNA actually has one more oxygen atom than DNA. Choice D is incorrect as DNA and RNA have different sugar molecules, with DNA having deoxyribose and RNA having ribose.

3. What percentage of the parents' offspring is predicted to have a cleft chin if one parent carries the recessive gene for a cleft chin (c) while the other parent does not?

• A. 25%
• B. 50%
• C. 0%
• D. 75%

Correct answer: C

Rationale: The correct answer is C (0%). If one parent carries the recessive gene for a cleft chin while the other parent does not carry it, none of their offspring is predicted to have a cleft chin. This is because the cleft chin trait is recessive, so for an offspring to express this trait, they would need to inherit the gene from both parents. In this scenario, none of the offspring will inherit the recessive gene from both parents, so the percentage of offspring predicted to have a cleft chin is 0%. Choices A, B, and D are incorrect because in this situation, the offspring will not express the cleft chin phenotype, although they could be carriers of the recessive gene.

4. At the beginning of meiosis, how many chromosomes does the diploid parent cell have?

• A. 23
• B. 24
• C. 46
• D. 54

Correct answer: C

Rationale: The correct answer is C: 46. At the start of meiosis, the diploid parent cell contains 46 chromosomes. During meiosis, the number of chromosomes is halved, resulting in each gamete having 23 chromosomes. Choice A (23) is incorrect because that is the number of chromosomes in a human gamete, not the parent cell. Choice B (24) and Choice D (54) are also incorrect as they do not reflect the correct number of chromosomes in a diploid parent cell at the beginning of meiosis.

5. The cellular membrane contributes to all except which of the following?

• A. Cell energy production
• B. Cell permeability
• C. Cell communication
• D. Cell protection

Correct answer: A

Rationale: The cellular membrane is involved in regulating cell permeability, communication, and protection. However, it is not directly involved in energy production. Choice A is the correct answer because the cellular membrane does not produce energy; instead, it regulates the passage of molecules in and out of the cell. Choices B, C, and D are incorrect because the cell membrane plays key roles in controlling what enters and exits the cell, facilitating communication between cells, and providing structural support and protection to the cell.

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