Nokea
Choose the CORRECT statement regarding events that occur in metaphase II.
- A. Sister chromatids may no longer be identical to each other.
- B. Homologous chromosomes line up at metaphase plat
- C. Crossing over between homologous chromosomes occurs.
- D. Homologous chromosomes begin to separat
Correct Answer: A
Rationale: Correct Answer: A - Sister chromatids may no longer be identical to each other.
Rationale:
1. In metaphase II, sister chromatids align at the metaphase plate.
2. During meiosis II, sister chromatids separate and move to opposite poles.
3. Due to potential crossing over in meiosis I, sister chromatids may not be identical in meiosis II.
4. This variability contributes to genetic diversity in the resulting gametes.
Summary:
B: Homologous chromosomes do not line up in metaphase II; they already separated in meiosis I.
C: Crossing over occurs in meiosis I, not in meiosis II.
D: Homologous chromosomes start to separate in anaphase I, not metaphase II.
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Where does implantation of the blastocyst occur?
- A. uterine tubes
- B. endometrium
- C. cervix
- D. ovary
Correct Answer: B
Rationale: The correct answer is B: endometrium. After fertilization, the blastocyst travels through the uterine tubes and implants into the endometrium for further development. The endometrium is the inner lining of the uterus where implantation occurs to establish pregnancy. The uterine tubes (choice A) are the site of fertilization, but not implantation. The cervix (choice C) is the lower part of the uterus that connects to the vagina and does not play a role in implantation. The ovary (choice D) is where the egg is released during ovulation and not the site of implantation.
Which cells are present in a male age five?
- A. spermatocytes
- B. spermatozoa
- C. spermatogonia
- D. spermatid
Correct Answer: C
Rationale: The correct answer is C: spermatogonia. At the age of five, boys have not reached puberty yet, so they do not produce sperm cells. Spermatogonia are the precursor cells that give rise to sperm cells later in puberty. Spermatocytes are the cells that undergo meiosis to form sperm cells, spermatozoa are mature sperm cells, and spermatids are the immediate precursors to sperm cells. Therefore, the only cells present in a male age five would be spermatogonia, as they are the early-stage cells in the process of spermatogenesis.
Wolffian duct is also known as ____________.
- A. Mesonephric duct
- B. Ejaculatory duct
- C. Major sublingual duct
- D. Cystic duct
Correct Answer: A
Rationale: The correct answer is A: Mesonephric duct. The Wolffian duct is also known as the mesonephric duct because it develops in the embryo to form the male reproductive system. It gives rise to various structures such as the epididymis, vas deferens, and seminal vesicles. The other choices are incorrect because the ejaculatory duct is formed by the union of the vas deferens and seminal vesicle, the major sublingual duct is associated with saliva production, and the cystic duct is part of the biliary system and not related to the male reproductive system.
Which of the following is not a role of semen?
- A. Semen dilutes sperm.
- B. The acidity of semen helps neutralize the pH environment of a female's vagina
- C. Semen contains enzymes that enhance sperm motility.
- D. Semen contains antibiotic chemicals that destroy bacteria
Correct Answer: C
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During ovulation, the oocyte passes into the _____.
- A. uterine tube
- B. uterus
- C. pelvic cavity
- D. ovary
Correct Answer: A
Rationale: The correct answer is A: uterine tube. During ovulation, the mature oocyte is released from the ovary and travels through the uterine tube (fallopian tube) towards the uterus for potential fertilization. The uterine tube is the pathway for the oocyte to reach the uterus. Choices B, C, and D are incorrect because the oocyte does not directly pass into the uterus, pelvic cavity, or ovary during ovulation.