Nursing Elites

1. Tim, a 27-year-old man, has unusually narrow shoulders, low muscle mass, and has no facial and body hair. His doctor recently prescribed testosterone replacement therapy to him. Tim is most likely suffering from:

• A. Phenylketonuria (PKU).
• B. Cystic fibrosis.
• C. Klinefelter syndrome.
• D. Huntington’s disease (HD).

Correct answer: C

Rationale: Tim's physical characteristics, such as narrow shoulders, low muscle mass, and lack of facial and body hair, are typical signs of Klinefelter syndrome, a genetic condition where males have an extra X chromosome (XXY). This leads to underdeveloped testes and reduced testosterone production, resulting in features like gynecomastia, sparse facial and body hair, and reduced muscle mass. Testosterone replacement therapy is commonly used to address the hormonal imbalance in individuals with Klinefelter syndrome. Phenylketonuria (PKU) is a metabolic disorder unrelated to the symptoms described in Tim's case. Cystic fibrosis is a genetic respiratory condition that does not present with the physical characteristics mentioned. Huntington’s disease (HD) is a neurodegenerative disorder primarily affecting motor function and cognition, not physical appearance and muscle mass.

2. Which of the following processes happen during mitosis?

• A. Strands of deoxyribonucleic acid (DNA) break apart.
• B. Adenine combines with its appropriate partner, cytosine.
• C. Sperm and ova cells are created.
• D. Twenty-three chromosomes are created.

Correct answer: A

Rationale: The correct process that happens during mitosis is the breaking apart, replication, and division of DNA strands into two new cells, each with the same number of chromosomes as the original cell. Choice B is incorrect because it describes base pairing in DNA, not a process specific to mitosis. Choice C is incorrect as the creation of sperm and ova cells is related to meiosis, not mitosis. Choice D is incorrect because chromosomes are not created during mitosis; they are replicated and divided equally between the daughter cells.

3. When both alleles' effects are shown, there is said to be:

• A. codominance.
• B. preponderance.
• C. ascendance.
• D. concurrence.

Correct answer: A

Rationale: The correct answer is A: codominance. Codominance refers to a genetic scenario where both alleles in a gene pair are fully expressed, leading to a phenotype that displays traits from both alleles equally. This is distinct from incomplete dominance where the traits blend. Choices B, C, and D are incorrect. Preponderance does not specifically relate to the expression of alleles. Ascendance and concurrence do not describe the genetic concept of codominance where both alleles are fully expressed.

4. Do neural tube defects cause an elevation in the alpha-fetoprotein (AFP) level in the mother’s blood?

• A. Yes
• B. No
• C. Possibly
• D. Never

Correct answer: A

Rationale: Yes, neural tube defects can cause an elevation in AFP levels in the mother’s blood. AFP levels are often used as a screening marker during pregnancy to detect neural tube defects. Choice B is incorrect because an elevation in AFP levels can indeed occur in the presence of neural tube defects. Choice C is not the best option as it leaves room for uncertainty when the relationship between neural tube defects and AFP elevation is well-established. Choice D is incorrect as neural tube defects are known to influence AFP levels in the maternal blood.

5. After mitosis, the genetic code is identical in new cells unless _________ occur through radiation or other environmental influences.

• A. reductions
• B. expulsions
• C. conceptions
• D. mutations

Correct answer: D

Rationale: After mitosis, the genetic code is typically preserved and remains identical in the new cells. However, mutations can occur due to radiation or environmental influences, leading to changes in the DNA sequence and potentially altering the genetic code. Therefore, the correct answer is 'mutations.' Choices A, B, and C are incorrect because reductions, expulsions, and conceptions do not accurately describe the changes in the genetic code that can result from external factors. Mutations are the only option that reflects the alteration in the genetic code caused by external influences, making it the correct choice in this context.

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