Nursing Elites

1. When both of the alleles for a trait, such as hair color, are the same, the person is said to be _____ for that trait.

• A. monozygous
• B. dizygous
• C. homozygous
• D. hemizygous

Correct answer: C

Rationale: A person is homozygous for a trait when they have two identical alleles for that trait. In this case, both alleles are the same, indicating a homozygous genotype. Choice A, 'monozygous,' is incorrect as it refers to identical twins originating from a single fertilized egg. Choice B, 'dizygous,' is also incorrect as it refers to fraternal twins or individuals that develop from two separate fertilized eggs. Choice D, 'hemizygous,' is incorrect because it describes a genetic condition where only one allele is present in a diploid organism, typically related to genes on the sex chromosomes.

2. Does the probability of having a child with Down’s syndrome increase with the age of the parents?

• A. TRUE
• B. FALSE
• C. Sometimes
• D. Never

Correct answer: A

Rationale: The correct answer is A: TRUE. Advanced parental age, particularly maternal age, is associated with an increased risk of Down's syndrome in offspring. As parents get older, the likelihood of having a child with Down's syndrome increases. Choices B, C, and D are incorrect because the risk of Down's syndrome is known to rise with parental age, especially maternal age, due to the increased likelihood of chromosomal abnormalities during egg formation.

3. _____ is a type of estrogen, prescribed in the 1940s and 1950s to pregnant women, that is said to have caused testicular, vaginal, and cervical cancer in some offspring.

• A. Androsterone
• B. Adiponectin
• C. Progestin
• D. Diethylstilbestrol

Correct answer: D

Rationale: Diethylstilbestrol (DES) is a synthetic estrogen that was prescribed to pregnant women in the 1940s and 1950s to prevent miscarriages. However, it was later discovered that DES exposure in utero could lead to health issues in offspring, including an increased risk of testicular, vaginal, and cervical cancer. Choice A, Androsterone, is a steroid hormone produced in small amounts in humans and unlikely to be associated with the adverse effects described. Choice B, Adiponectin, is a protein hormone that plays a role in regulating glucose levels and fatty acid breakdown, not related to the adverse effects mentioned. Choice C, Progestin, is a synthetic form of progesterone used in birth control and hormone therapy, not linked to the specific health concerns associated with DES exposure.

4. 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.

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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