Nokea
Which of the following events does NOT lead to genetic variation?
- A. Independent assortment of chromosomes during meiosis.
- B. Random fertilization between ovum and sperm.
- C. Crossing over between homologous chromosomes during meiosis I.
- D. Crossing over between homologous chromosomes during meiosis II.
Correct Answer: D
Rationale: The correct answer is D. Crossing over between homologous chromosomes during meiosis II does not lead to genetic variation. This is because crossing over occurs during meiosis I, not meiosis II. Meiosis II is when the separated chromatids are pulled apart to form haploid cells. Independent assortment of chromosomes during meiosis (A) and random fertilization between ovum and sperm (B) both contribute to genetic variation by creating unique combinations of alleles. Crossing over between homologous chromosomes during meiosis I (C) also leads to genetic variation by exchanging genetic material between homologous chromosomes.
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The female Bartholin glands correspond to the male _____.
- A. prostate
- B. Cowper's
- C. seminal vesicle
- D. glans
Correct Answer: B
Rationale: The female Bartholin glands are homologous to the male Cowper's glands. Both glands secrete fluid to lubricate the reproductive tract during sexual arousal. The prostate gland (choice A) is not the correct answer as it is a different structure that produces seminal fluid. The seminal vesicles (choice C) secrete a significant portion of the seminal fluid but are not the male counterpart to the Bartholin glands. The glans (choice D) refers to the tip of the penis and is not the correct counterpart to the Bartholin glands. Therefore, the correct answer is B, Cowper's glands.
Which term includes the other terms?
- A. spermatozoa
- B. alkaline mucus
- C. semen
- D. fructose
Correct Answer: C
Rationale: The correct answer is C: semen. Semen is the fluid that contains spermatozoa, alkaline mucus, and fructose. Spermatozoa are the male reproductive cells, alkaline mucus helps neutralize vaginal acidity, and fructose provides energy for sperm. Semen is the combination of these components, making it the term that encompasses all the other terms listed. A: spermatozoa is incorrect because it is just one component of semen. B: alkaline mucus is incorrect as it is a separate component in semen. D: fructose is incorrect because it is also just one component found in semen.
Which of the following is a surgical procedure in which a pendulous breast is lifted and fixed to the chest wall?
- A. Mastostomy
- B. Mastectomy
- C. Mastopexy
- D. Mesopexy
Correct Answer: C
Rationale: The correct answer is C: Mastopexy. This surgical procedure involves lifting and fixing a pendulous breast to the chest wall to achieve a more youthful and firmer appearance. It does not involve removal of breast tissue like in mastectomy (B) or creation of a new breast mound like in mastostomy (A). Mesopexy (D) is not a recognized surgical procedure for breast lifting.
Sperm production begins in the
- A. seminiferous tubules
- B. epididymis
- C. vas deferens
- D. ejaculatory duct
Correct Answer: A
Rationale: The correct answer is A: seminiferous tubules. Sperm production starts in the seminiferous tubules of the testes through a process called spermatogenesis, involving the division and maturation of germ cells. The other choices, B: epididymis, C: vas deferens, and D: ejaculatory duct, are incorrect as they are not sites of sperm production but rather play roles in sperm storage, transport, and ejaculation, respectively. The seminiferous tubules are specifically designed for sperm production, making them the correct choice in this context.
Which hormone is produced by the corpus luteum that helps maintain pregnancy?
- A. Estrogen
- B. Testosterone
- C. Progesterone
- D. Relaxin
Correct Answer: C
Rationale: The correct answer is C: Progesterone. The corpus luteum produces progesterone, which is essential for maintaining the uterine lining and supporting early pregnancy. Progesterone helps prevent contractions of the uterus and supports the development of the placenta. Estrogen (A) is important for the initial thickening of the uterine lining but does not play a direct role in maintaining pregnancy. Testosterone (B) is not involved in pregnancy maintenance. Relaxin (D) helps relax the uterine muscles but is not primarily responsible for maintaining pregnancy.