Nursing Elites

1. How are sister chromatids distinguished from homologous chromosomes in meiosis I?

• A. Sister chromatids share the same centromere, while homologous chromosomes have different centromeres.
• B. Sister chromatids have identical DNA sequences, while homologous chromosomes have slightly different sequences due to crossing over.
• C. Sister chromatids repel each other, while homologous chromosomes attract each other during synapsis.
• D. Sister chromatids separate during anaphase I, while homologous chromosomes separate during anaphase II.

Correct answer: B

Rationale: In meiosis I, sister chromatids are exact copies of each other, containing identical DNA sequences. On the other hand, homologous chromosomes are pairs of chromosomes, with one inherited from each parent, and they can have different versions of genes due to genetic recombination during crossing over in prophase I. Choice A is incorrect because homologous chromosomes naturally have different centromeres. Choice C is incorrect as sister chromatids and homologous chromosomes do not exhibit repulsion or attraction during synapsis. Choice D is incorrect as sister chromatids separate during anaphase II, not anaphase I, while homologous chromosomes separate during anaphase I.

2. What is the role of the kidneys in the body?

• A. To regulate body temperature
• B. To filter waste from the blood
• C. To produce hormones
• D. To transport oxygen

Correct answer: B

Rationale: The correct answer is B: To filter waste from the blood. The kidneys play a crucial role in filtering waste products and excess substances from the blood to form urine, which helps maintain fluid balance and eliminate toxins from the body. Choice A is incorrect because regulating body temperature is primarily controlled by the skin and other mechanisms. Choice C is incorrect as hormone production is mainly attributed to other organs like the endocrine glands. Choice D is incorrect as the transportation of oxygen is primarily facilitated by the lungs and circulatory system, not the kidneys.

3. What is the action of the triceps reflex?

• A. Forces contraction of the triceps and extension of the arm.
• B. Forces contraction of the biceps, relaxation of the biceps, and arm extension.
• C. Causes the triceps to contract, causing the forearm to supinate and flex.
• D. Causes the triceps to relax and the upper arm to pronate and extend.

Correct answer: A

Rationale: The triceps reflex causes the triceps muscle to contract, leading to the extension of the arm. This reflex is a protective response to sudden stretching of the triceps muscle, as seen when a physician taps the triceps tendon during a physical examination. Choice A is the correct answer as it accurately reflects the action of the triceps reflex. Choices B, C, and D are incorrect because they describe actions that are not associated with the triceps reflex. Biceps contraction, forearm supination, flexion, triceps relaxation, and pronation are not part of the triceps reflex arc.

4. During which developmental process does the first trimester of gestation roughly correspond?

• A. Embryogenesis
• B. Fertilization
• C. Meiosis
• D. Menstruation

Correct answer: A

Rationale: The correct answer is A: Embryogenesis. The first trimester of gestation involves the process of embryogenesis, where the basic structures of the embryo are formed. This period is critical for the development of major organ systems and the establishment of the embryo's overall body plan. Fertilization occurs at the beginning of pregnancy when the sperm fertilizes the egg, marking the start of embryonic development. Meiosis is a cell division process that produces gametes (sperm and egg cells) with half the number of chromosomes. Menstruation is the shedding of the uterine lining when pregnancy does not occur.

5. Which of the following statements regarding macrophages is incorrect?

• A. They are found abundantly in the blood
• B. They are larger than neutrophils
• C. They are long-lived
• D. They are made in the bone marrow as monocytes, called macrophages once they reach organs

Correct answer: A

Rationale: The correct answer is A. Macrophages are not found abundantly in the blood; they are present in tissues and organs. Macrophages are tissue-resident immune cells that play a key role in immune responses and are derived from monocytes produced in the bone marrow. Choice B is correct as macrophages are larger than neutrophils. Choice C is correct as macrophages are long-lived cells. Choice D is correct as macrophages originate in the bone marrow as monocytes and differentiate into macrophages once they migrate to various tissues and organs.

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