- Which of the following events occurs during the luteal phase of the menstrual cycle?
a) Ovulation
b) Follicular development
c) Progesterone secretion by the corpus luteum
d) Estrogen peaks and declines
Answer: c) Progesterone secretion by the corpus luteum
Explanation:
The luteal phase begins after ovulation. The ruptured follicle transforms into the corpus luteum, which secretes progesterone to maintain the endometrium in case of fertilization. If pregnancy does not occur, the corpus luteum degenerates, leading to a drop in progesterone and the onset of menstruation.
- The sperm’s ability to fertilize an egg is acquired in which part of the male reproductive system?
a) Testes
b) Prostate gland
c) Epididymis
d) Vas deferens
Answer: c) Epididymis
Explanation:
Sperm acquire the ability to fertilize an egg during their maturation in the epididymis. The process involves gaining motility and the ability to recognize and penetrate the egg’s protective layers.
- The chorionic villi are involved in:
a) Nutrient and gas exchange between the mother and fetus
b) Protection of the fetus from infections
c) Hormonal secretion for lactation
d) Maintenance of amniotic fluid levels
Answer: a) Nutrient and gas exchange between the mother and fetus
Explanation:
Chorionic villi are finger-like projections that extend into the endometrium and form part of the placenta. They play a crucial role in facilitating the exchange of nutrients, gases, and waste between the maternal and fetal blood.
- Which of the following occurs during capacitation of sperm?
a) Sperm mature in the testes
b) Sperm become motile in the epididymis
c) Sperm undergo biochemical changes to fertilize the egg
d) Sperm are stored in the seminal vesicle
Answer: c) Sperm undergo biochemical changes to fertilize the egg
Explanation:
Capacitation is a process that occurs in the female reproductive tract after ejaculation, where sperm undergo physiological changes, enhancing their ability to penetrate the egg’s zona pellucida and fertilize it.
- In a 28-day menstrual cycle, on which day does ovulation typically occur?
a) 1st day
b) 7th day
c) 14th day
d) 21st day
Answer: c) 14th day
Explanation:
In a typical 28-day menstrual cycle, ovulation occurs around the 14th day. This is when the mature egg is released from the ovary and is available for fertilization. The timing may vary depending on the length of the individual’s cycle.
- Which of the following is true about the placenta?
a) It secretes hCG
b) It stores oxygen for the fetus
c) It produces prolactin during pregnancy
d) It prevents maternal hormones from affecting the fetus
Answer: a) It secretes hCG
Explanation:
The placenta secretes human chorionic gonadotropin (hCG), which helps maintain the corpus luteum and the production of progesterone in the early stages of pregnancy. This hormone is also detected in pregnancy tests.
- Which of the following occurs when the zona pellucida of the ovum is penetrated by a sperm?
a) Completion of the first meiotic division
b) Completion of the second meiotic division
c) Fusion of the nucleus of the sperm and egg
d) Formation of the corpus luteum
Answer: b) Completion of the second meiotic division
Explanation:
Once a sperm penetrates the zona pellucida and fuses with the egg, the secondary oocyte completes its second meiotic division, resulting in the formation of a mature ovum and the release of a polar body.
- What role does relaxin play during pregnancy?
a) Stimulates the secretion of milk
b) Relaxes the pubic symphysis and cervix
c) Stimulates uterine contractions
d) Initiates the release of oxytocin
Answer: b) Relaxes the pubic symphysis and cervix
Explanation:
Relaxin is a hormone produced during pregnancy that helps relax the pubic symphysis (the joint between the two halves of the pelvis) and softens the cervix to prepare for childbirth.
- Which of the following happens during the acrosome reaction?
a) The sperm is activated for motility
b) Enzymes are released to digest the zona pellucida
c) The sperm completes meiosis
d) The sperm and egg nuclei fuse
Answer: b) Enzymes are released to digest the zona pellucida
Explanation:
During the acrosome reaction, enzymes are released from the acrosome (a cap-like structure on the head of the sperm) to digest the zona pellucida, allowing the sperm to penetrate and fertilize the egg.
- What is the function of the trophoblast in early pregnancy?
a) It becomes the embryo
b) It forms the amniotic sac
c) It secretes hCG to maintain the corpus luteum
d) It forms the fetal part of the umbilical cord
Answer: c) It secretes hCG to maintain the corpus luteum
Explanation:
The trophoblast, which is the outer layer of the blastocyst, secretes human chorionic gonadotropin (hCG). This hormone maintains the corpus luteum, ensuring the continued production of progesterone, which is essential for sustaining the pregnancy.
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