Nursing Elites

1. Chromosomes contain thousands of segments called:

• A. nuclei.
• B. nodes.
• C. capillaries.
• D. genes.

Correct answer: D

Rationale: Chromosomes are structures composed of DNA and genes. Genes are the functional segments within chromosomes that encode specific traits and characteristics. The other choices ('nuclei,' 'nodes,' 'capillaries') do not accurately describe the segments found within chromosomes and are unrelated to their structure or function.

2. Once the testes have developed in the embryo, they begin to produce male sex hormones, or _____.

• A. androgens
• B. genotypes
• C. blastocysts
• D. teratogens

Correct answer: A

Rationale: Androgens are male sex hormones, such as testosterone, produced by the testes after they have developed in the embryo. Androgens are responsible for the development of male secondary sexual characteristics. Genotypes refer to an individual's genetic makeup, not hormones. Blastocysts are early stage embryos, not male sex hormones. Teratogens are substances that can interfere with fetal development, not male sex hormones produced by the testes.

3. Which of the following statements is true about Tay-Sachs disease?

• A. It is most commonly found among children in Jewish families of Eastern European background.
• B. Children who have this disease suffer from excessive production of mucus in the lungs and pancreas.
• C. It is most commonly found among children in Asian American families.
• D. Children who have this disease suffer from muscular dystrophy characterized by a weakening of the muscles.

Correct answer: A

Rationale: The correct answer is A. Tay-Sachs disease is most commonly found among Jewish families of Eastern European descent. It is a fatal genetic disorder that affects the nervous system. Choice B is incorrect because Tay-Sachs disease does not involve excessive mucus production in the lungs and pancreas. Choice C is incorrect as it states that Tay-Sachs disease is most commonly found among Asian American families, which is inaccurate. Choice D is also incorrect because Tay-Sachs disease does not cause muscular dystrophy characterized by weakening of the muscles.

4. In the context of an average ejaculation, which of the following statements is true about sperm?

• A. The average count of sperm in the ejaculate is 2.5 billion.
• B. Sperm in the ejaculate find the ovum by following the current of the fluid coming from the cervix.
• C. Only 1 in 1,000 sperm in the ejaculate will ever approach an ovum.
• D. Most of the sperm in the ejaculate move about in a random pattern in the vagina.

Correct answer: C

Rationale: Out of millions of sperm released during ejaculation, only a small fraction, about 1 in 1,000, will approach the ovum. This statement is true as sperm face many obstacles and challenges on their journey to reach and fertilize an ovum. Choice A is incorrect because the average count of sperm in an ejaculate is typically in the millions, not billions. Choice B is incorrect as sperm do not find the ovum by following the current of fluid; they navigate using other mechanisms. Choice D is incorrect because while some sperm may move randomly in the vagina, the ones that approach the ovum do so through a more purposeful and directed movement.

5. Rico is a man who has enlarged breasts and suffers from mild mental retardation. He has a problem learning languages, and his body produces less of the male sex hormone testosterone than normal males. Rico is most likely suffering from:

• A. Klinefelter syndrome.
• B. Tay-Sachs disease.
• C. Turner syndrome.
• D. Down syndrome.

Correct answer: A

Rationale: Rico's symptoms align with Klinefelter syndrome, which is characterized by an extra X chromosome in males (XXY). Enlarged breasts (gynecomastia), mild mental retardation, learning difficulties, and reduced testosterone production are common features of Klinefelter syndrome. Choice B, Tay-Sachs disease, is a genetic disorder that affects the nervous system and is not associated with the symptoms described. Choice C, Turner syndrome, occurs in females with a missing or partially missing X chromosome and does not fit Rico's profile. Choice D, Down syndrome, is caused by an extra copy of chromosome 21 and typically does not present with the symptoms mentioned for Rico.

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