Nursing Elites

1. Individuals with Klinefelter syndrome produce:

• A. less estrogen than normal males.
• B. less testosterone than normal males.
• C. less adenine than normal males.
• D. less thymine than normal males.

Correct answer: B

Rationale: Individuals with Klinefelter syndrome have an extra X chromosome (XXY), leading to reduced production of testosterone, the primary male sex hormone. This deficiency can result in various physical and developmental characteristics associated with the syndrome. Estrogen levels may actually be relatively elevated due to the imbalance between testosterone and estrogen. Choices C and D are incorrect as adenine and thymine are nucleotide bases found in DNA and are not related to hormone production.

2. What is a procedure for using ultrasonic sound waves to create a picture of an embryo or fetus?

• A. Phenotype
• B. Sonogram
• C. Genotype
• D. Alpha-fetoprotein (AFP) assay

Correct answer: B

Rationale: A sonogram, also known as an ultrasound, is a procedure that utilizes sound waves to generate images of a developing embryo or fetus. This imaging technique is commonly used in prenatal care to monitor fetal development and identify any potential abnormalities. Choices A, C, and D are incorrect because a phenotype refers to an individual's observable traits resulting from genetic and environmental influences, a genotype is an individual's genetic makeup, and an alpha-fetoprotein (AFP) assay is a blood test used to screen for certain birth defects.

3. What is the central layer of the embryo from which the bones and muscles develop?

• A. neural tube
• B. mesoderm
• C. ectoderm
• D. umbilical cord

Correct answer: B

Rationale: The correct answer is mesoderm. The mesoderm is the middle layer of the embryo that gives rise to the bones, muscles, and other connective tissues. The neural tube (choice A) develops into the nervous system, not bones and muscles. The ectoderm (choice C) forms the skin and nervous system, not bones and muscles. The umbilical cord (choice D) is a structure that connects the developing fetus to the placenta; it is not a layer of the embryo that gives rise to bones and muscles.

4. 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.

5. In the structure of deoxyribonucleic acid (DNA), which of the following bases combines with thymine?

• A. Cytosine
• B. Adenine
• C. Rhodamine
• D. Serine

Correct answer: B

Rationale: The correct answer is B: Adenine. In the structure of DNA, adenine pairs with thymine through hydrogen bonding, forming one of the complementary base pairs that make up the double helix structure of DNA. Cytosine pairs with guanine, not thymine. Rhodamine and serine are not DNA bases and do not participate in DNA base pairing. Therefore, choices A, C, and D are incorrect.

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