Nursing Elites

1. Which of the following is NOT a typical component of healthy semen?

• A. Sperm
• B. Fructose (sugar)
• C. Prostaglandins
• D. Urine

Correct answer: D

Rationale: Healthy semen is composed of sperm, fructose (sugar), and prostaglandins. Urine is not a typical component of semen. While semen is ejaculated during sexual activity, urine is expelled through a separate pathway in the male reproductive system. Therefore, the correct answer is 'Urine.' Choices A, B, and C are all components found in healthy semen.

2. What is the coefficient of oxygen in the balanced chemical equation for the combustion of methane (CH₄)?

• A. 1
• B. 2
• C. 3
• D. 4

Correct answer: B

Rationale: In the balanced chemical equation for the combustion of methane, CH₄ + 2O₂ → CO₂ + 2H₂O, the coefficient of oxygen (O₂) is 2. This indicates that two molecules of oxygen are required to react with one molecule of methane to produce carbon dioxide and water, ensuring the equation is balanced. Choice A is incorrect because the coefficient of oxygen is not 1 but 2. Choices C and D are incorrect as they do not represent the correct coefficient of oxygen in the balanced equation. Understanding the coefficients in a balanced chemical equation is crucial for accurately representing the stoichiometry of the reaction.

3. In an experiment where five tropical plants are kept at varying humidity levels in a greenhouse for three months, while one plant is left outside in normal conditions, with plant height measured weekly, what serves as the control of the experiment?

• A. Plant height for each tropical plant
• B. The plant left outside in normal conditions
• C. Humidity level readings in the greenhouse
• D. Amount of time used to study plant height

Correct answer: B

Rationale: The correct answer is B. The plant left outside in normal conditions acts as the control in the experiment. It provides a standard reference point for comparison to assess the impact of the varying humidity levels on the growth of the tropical plants. Choice A is incorrect because it refers to the dependent variable being measured, not the control. Choice C is incorrect as humidity levels in the greenhouse are part of the experimental conditions, not the control. Choice D is incorrect as the time used for studying plant height is a parameter of the experiment and not the control.

4. What is the process by which a fertilized egg implants itself in the lining of the uterus?

• A. Fertilization
• B. Implantation
• C. Gestation
• D. Parturition

Correct answer: B

Rationale: Implantation is the correct answer. It is the process where a fertilized egg attaches itself to the lining of the uterus to establish a pregnancy. Fertilization is the initial step where the sperm and egg fuse to form a zygote. Gestation refers to the period of fetal development within the uterus. Parturition is the process of giving birth and is not related to the implantation of the fertilized egg, which occurs earlier in the reproductive process.

5. Which statement most accurately compares and contrasts the structures of DNA and RNA?

• A. Both DNA and RNA have 4 nucleotide bases. Three of the bases are the same, but the fourth base is thymine in DNA and uracil in RNA.
• B. Both DNA and RNA have the same 4 nucleotide bases. However, the nucleotides bond differently in DNA compared to RNA.
• C. Both DNA and RNA have different numbers of nucleotide bases. DNA is a double helix while RNA is a single strand.
• D. Both DNA and RNA have a double helix structure. However, DNA contains 6 nucleotide bases and RNA contains 4 nucleotide bases.

Correct answer: A

Rationale: The correct answer is A because DNA and RNA both consist of 4 nucleotide bases, namely adenine, cytosine, and guanine, which are common in both. The key difference lies in the fourth base, which is thymine in DNA and uracil in RNA. This distinction is fundamental in understanding the structural variances between DNA and RNA. Choice B is incorrect as it incorrectly states that the nucleotides bond differently in DNA compared to RNA without specifying the crucial base differences. Choice C is inaccurate as it misrepresents the numbers of nucleotide bases in DNA and RNA, and incorrectly describes DNA as a double helix and RNA as a single strand, which is not related to the difference in bases. Choice D is incorrect as it inaccurately portrays DNA with 6 nucleotide bases and RNA with 4, which is not true; both DNA and RNA have 4 nucleotide bases, but with differences in one of the bases.

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