Nursing Elites

1. Before meiosis, a sperm cell:

• A. contains 46 chromosomes.
• B. contains two X chromosomes.
• C. is significantly larger than an egg cell.
• D. contains both an X and a Y chromosome.

Correct answer: A

Rationale: Before meiosis, a sperm cell contains 46 chromosomes. This is because sperm cells, like other somatic cells, have a diploid number of chromosomes. During meiosis, the number of chromosomes is halved to 23 to combine with an egg cell during fertilization. Choice B is incorrect because a sperm cell carries either an X or a Y chromosome, not both (Choice D). Choice C is incorrect as sperm cells are generally smaller than egg cells, which is an adaptation that aids in motility and penetration of the egg during fertilization.

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. Thalidomide was marketed in the 1960s as a treatment for:

• A. insomnia and nausea.
• B. infertility and impotence.
• C. Down syndrome.
• D. Turner syndrome.

Correct answer: A

Rationale: Thalidomide was initially marketed as a treatment for insomnia and nausea, particularly in pregnant women. However, it was later found to cause severe birth defects, leading to significant consequences. Choice B, infertility and impotence, is incorrect as thalidomide was not marketed for these conditions. Choices C and D, Down syndrome and Turner syndrome, are genetic conditions and not conditions for which thalidomide was intended as a treatment.

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. The embryo and fetus develop within a protective _______ in the uterus.

• A. amniotic sac
• B. umbilical cord
• C. neural tube
• D. embryonic disk

Correct answer: A

Rationale: The correct answer is A, the amniotic sac. The amniotic sac is a fluid-filled structure that surrounds and protects the developing embryo and fetus in the uterus. It provides a cushion against external pressure, allows for movement and growth, and helps maintain a stable environment for the developing fetus. Choices B, C, and D are incorrect. The umbilical cord connects the fetus to the placenta and serves as a conduit for nutrients and waste; the neural tube is a structure that forms the central nervous system in early embryonic development; and the embryonic disk is a structure that forms during gastrulation, one of the early stages of embryonic development.

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