Nursing Elites

1. 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.

2. Humans begin life as a single cell that divides repeatedly. This cell is known as a(n):

• A. zygote.
• B. gonadotrope.
• C. embryo.
• D. chromaffin.

Correct answer: A

Rationale: A zygote is the correct answer. It is the initial cell formed when a sperm cell fertilizes an egg cell, marking the beginning of human development. Choice B, gonadotrope, is incorrect as it refers to a type of hormone-secreting cell in the pituitary gland. Choice C, embryo, is incorrect as it is the stage of development after the zygote has implanted into the uterine wall and undergone initial cell divisions. Choice D, chromaffin, is incorrect as it refers to cells found in the adrenal medulla that produce and store catecholamines.

3. Is a low sperm count or lack of sperm the most common infertility problem in men?

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

Correct answer: A

Rationale: A low sperm count or lack of sperm is indeed one of the most common causes of infertility in men. Factors such as hormonal imbalances, genetic issues, reproductive anatomy problems, and lifestyle factors can also contribute to male infertility. Choice B is incorrect because a low sperm count is a prevalent issue among men facing infertility, making it a common problem. Choices C and D are incorrect as they do not accurately reflect the prevalence of low sperm count as a cause of infertility in men.

4. 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.

5. 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.

Similar Questions