Nokea
Choose the correct sequence of human embryonic development.
- A. Fertilization - organogenesis - gastrulation - cleavag
- B. Cleavage - fertilization - gastrulation - organogenesis.
- C. Fertilization - cleavage - organogenesis - gastrulation.
- D. Fertilization - cleavage - gastrulation- organogenesis.
Correct Answer: D
Rationale: The correct sequence of human embryonic development is D: Fertilization - cleavage - gastrulation - organogenesis.
1. Fertilization: The union of egg and sperm forms a zygote.
2. Cleavage: Zygote undergoes rapid cell division without growth.
3. Gastrulation: Formation of three germ layers (ectoderm, mesoderm, endoderm).
4. Organogenesis: Organ formation from germ layers.
This sequence reflects the chronological order of events in early human development.
Choice A is incorrect as organogenesis occurs after gastrulation.
Choice B is incorrect as fertilization should precede cleavage.
Choice C is incorrect as organogenesis occurs after gastrulation.
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Which of the following is the primary sign of breast cancer?
- A. A bloody discharge from the nipple
- B. A dimpling of the skin over the lesion
- C. A retraction of the nipple
- D. A painless mass in the breast
Correct Answer: D
Rationale: A painless mass is often the first noticeable sign of breast cancer.
Which of the following is NOT a part of
- A. labor a male's testis?
- B. menarche
- C. seminiferous tubule
- D. menstruation
Correct Answer: B
Rationale: The correct answer is B: menarche. Menarche refers to the onset of a female's first menstrual period, not related to male reproductive anatomy. Choice A, labor a male's testis, involves the process of childbirth and is not related to male reproductive anatomy. Choice C, seminiferous tubule, is a part of the male reproductive system where sperm is produced. Choice D, menstruation, is the monthly shedding of the uterine lining in females, not related to male reproductive anatomy. Therefore, menarche is the only choice that does not pertain to male reproductive anatomy.
Which structure helps regulate the temperature of the testes?
- A. Dartos muscle
- B. Tunica vaginalis
- C. Tunica albuginea
- D. Seminiferous tubules
Correct Answer: A
Rationale: The correct answer is A: Dartos muscle. The Dartos muscle is a layer of smooth muscle in the scrotum that contracts and relaxes to regulate the temperature of the testes by adjusting their distance from the body for temperature control. The other choices are incorrect because:
B: Tunica vaginalis is a serous membrane that surrounds the testes, providing support and lubrication.
C: Tunica albuginea is a dense fibrous membrane that covers the testes, providing structural support.
D: Seminiferous tubules are the site of sperm production in the testes, but do not play a direct role in temperature regulation.
Which of the following sets of tissues are all part of a developing follicle.
- A. granulosa cells, theca, corpus luteum
- B. theca, acrosome, antrum
- C. oocyte, corpus luteum, granulosa cells
- D. . zona pellucida, cumulus oophorous, theca
Correct Answer: D
Rationale: The correct answer is D because all the tissues mentioned (zona pellucida, cumulus oophorous, theca) are indeed part of a developing follicle. The zona pellucida is the glycoprotein layer surrounding the oocyte, the cumulus oophorous is a cluster of granulosa cells surrounding the oocyte, and the theca is a layer of connective tissue surrounding the follicle.
Choice A is incorrect because the corpus luteum is not part of a developing follicle. Choice B is incorrect because the acrosome is a structure in sperm, not the follicle. Choice C is incorrect because the corpus luteum is not part of a developing follicle, and the oocyte is already present within the follicle but is not considered a part of it.
The male sex of the child involves the following during fecundation:
- A. the spermatozoon should contain the X sex chromosome;
- B. the spermatozoon should contain the Y sex chromosome;
- C. the ovule should contain the contain the Y sex chromosome;
- D. the spermatozoon should contain the Y sex chromosome and the ovule should contain the contain the X sex chromosome;
Correct Answer: B
Rationale: Step 1: At fertilization, the sperm contributes either an X or Y sex chromosome.
Step 2: The ovum always contributes an X sex chromosome.
Step 3: If the sperm carries the Y chromosome, the resulting child will be male.
Therefore, the correct choice is B.
Summary:
A: Incorrect. If the sperm contains the X chromosome, the child will be female.
C: Incorrect. Ovule always contains an X chromosome.
D: Incorrect. This choice combines correct and incorrect information, as the sperm must contain the Y chromosome for a male child.