Block 7 Fertilization & Pregnancy MCQ's
.JPG "Block 7 Fertilization & Pregnancy MCQ")
Questions and Answers
- 1.
During the process of fertilization of an oocyte, what function do oocyte cortical granules have, and what is their site of action?
- A.
A
- B.
B
- C.
C
- D.
D
- E.
E
Correct Answer
D. DExplanation
During the process of fertilization of an oocyte, oocyte cortical granules have the function of preventing polyspermy, which is the fertilization of an egg by multiple sperm. Their site of action is the zona pellucida, which is the protective layer surrounding the oocyte. The cortical granules release their contents into the zona pellucida, causing it to harden and form a barrier that prevents additional sperm from entering the oocyte.Rate this question:
-
- 2.
A 30-year-old female came to your office with a complaint of infertility. Five years ago she had a daughter who was delivered at full term. However, she developed severe bleeding postpartum, lost consciousness, and experienced severe hypotension. She was in the intensive care unit for several days during which time she began to have unusually large urine volumes (> 0.5 L/hr). She was successfully stabilized and treated with a brief course of glucocorticoids. She has not had normal menstrual periods for the past four years. Recent laboratory tests revealed low plasma levels of estradiol, luteinizing hormone (LH), and follicle stimulating hormone (F51-1). What is the most likely explanation for her infertility?
- A.
Involution of the fallopian tubes.
- B.
Gonadotropin releasing hormone (GnRH) tumor in the hypothalamus
- C.
Destruction of primordial follicles
- D.
Loss of normal pituitary function.
- E.
Hypersecretion of adrenal cortical hormones
Correct Answer
D. Loss of normal pituitary function.Explanation
The patient's history of severe bleeding postpartum, followed by large urine volumes and low plasma levels of estradiol, LH, and FSH, suggests a disruption in the hypothalamic-pituitary-gonadal axis. This axis is responsible for regulating the menstrual cycle and fertility. The most likely explanation for her infertility is loss of normal pituitary function, which can result in decreased secretion of LH and FSH, leading to anovulation and infertility. The other options (involution of the fallopian tubes, GnRH tumor, destruction of primordial follicles, hypersecretion of adrenal cortical hormones) do not explain the patient's symptoms and laboratory findings.Rate this question:
-
- 3.
A female in her early twentes takes an oral contraceptive pill which contains a synthetic progestin. What is the most likely explanation for the contraceptive action of this drug?
- A.
Replacement of the LH surge by an FSH surge.
- B.
Abolition of the LH surge
- C.
Enhanced positive feedback of the hypothalamic-pituitary-gonadal axis.
- D.
Increased conversion of testosterone to estradiol.
- E.
Inadequate decidualization of the uterus.
Correct Answer
E. Inadequate decidualization of the uterus.Explanation
The most likely explanation for the contraceptive action of the oral contraceptive pill containing a synthetic progestin is inadequate decidualization of the uterus. Progestins are synthetic hormones that mimic the actions of progesterone in the body. Progesterone is necessary for the development and maintenance of the uterine lining (endometrium) to support implantation of a fertilized egg. Inadequate decidualization of the uterus refers to the insufficient development of the endometrium, making it less receptive to implantation and reducing the chances of pregnancy. This is one of the mechanisms by which progestins prevent pregnancy.Rate this question:
-
- 4.
A male (Mr. K) in his early twenties comes to your office with concerns that he and his wife (Mrs. K) have not been able to conceive. When you do a review of systems and brief history, you note that this man has had chronic respiratory problems typified by inability to clear his airways of mucous. You then proceed to do a physical examination. When you auscultate for breath sounds, you hear some crackles (rales). Both testes have descended and there do not appear to be any masses in the testes. Otherwise, your physical exam indicates that he is healthy. The patient informs you that he is able to achieve and maintain an erection. Moreover, he believes that his ejaculation is normal. To gather additional information that might explain a possible fertility problem in this young man, you obtain blood and ask that he provide you with a semen sample. The results of the blood work are presented in the accompanying table. When his semen was analyzed, it was found to have a normal number of sperm per milliliter. However, the laboratory report commented that more than 50% of the sperm had motility problems. You are asked by the chief of the urology service to investigate if there might be any connection between this young man's respiratory problems and his apparent infertility. Table; Blood work analysis Patient Normal range LH (mIU/m1) 20 6-23 FSH (rnIU/m1) 18 4-25 Testosterone (ngidL) 900 300-1,100 Total T4 (pgicIL) 10 5-12 Hb (g/dL) 15 13.5-17.5 If this patient has a chronic respiratory problem, what similar problem may explain this condition and infertility?
- A.
Emphysema
- B.
Immunological disorder of the vagina
- C.
Hyperprolactinemia
- D.
Kartagener's syndrome
- E.
Klinefelter syndrome
Correct Answer
D. Kartagener's syndromeExplanation
Kartagener's syndrome is a genetic disorder that affects the structure and function of cilia in the body. This syndrome is characterized by chronic respiratory problems, such as the inability to clear airways of mucus, which is seen in the patient's case. Kartagener's syndrome can also lead to infertility due to the impaired function of cilia in the reproductive organs, including the fallopian tubes and sperm cells. Therefore, it is likely that the patient's chronic respiratory problems and infertility are connected due to Kartagener's syndrome.Rate this question:
-
- 5.
A male (Mr. K) in his early twenties comes to your office with concerns that he and his wife (Mrs. K) have not been able to conceive. When you do a review of systems and brief history, you note that this man has had chronic respiratory problems typified by inability to clear his airways of mucous. You then proceed to do a physical examination. When you auscultate for breath sounds, you hear some crackles (rales). Both testes have descended and there do not appear to be any masses in the testes. Otherwise, your physical exam indicates that he is healthy. The patient informs you that he is able to achieve and maintain an erection. Moreover, he believes that his ejaculation is normal. To gather additional information that might explain a possible fertility problem in this young man, you obtain blood and ask that he provide you with a semen sample. The results of the blood work are presented in the accompanying table. When his semen was analyzed, it was found to have a normal number of sperm per milliliter. However, the laboratory report commented that more than 50% of the sperm had motility problems. You are asked by the chief of the urology service to investigate if there might be any connection between this young man's respiratory problems and his apparent infertility. Table; Blood work analysis Patient Normal range LH (mIU/m1) 20 6-23 FSH (rnIU/m1) 18 4-25 Testosterone (ngidL) 900 300-1,100 Total T4 (pgicIL) 10 5-12 Hb (g/dL) 15 13.5-17.5 Which of the following statements may account for the apparent infertility problem in this patient?
- A.
Insufficient supply (release) of FSH
- B.
Lack of production of inhibin
- C.
Inability of sperms to undergo capacitation
- D.
Inability of Leydig cells to respond to LH
- E.
Lack of dynein
Correct Answer
E. Lack of dyneinExplanation
The lack of dynein may account for the apparent infertility problem in this patient. Dynein is a motor protein that is necessary for the movement of sperm. Without dynein, the sperm may have motility problems and be unable to swim properly, which can lead to infertility. This is supported by the fact that the patient's semen analysis showed that more than 50% of the sperm had motility problems. The other options, such as insufficient supply of FSH or inability of Leydig cells to respond to LH, do not directly explain the motility problems observed in the semen analysis.Rate this question:
-
- 6.
A male (Mr. K) in his early twenties comes to your office with concerns that he and his wife (Mrs. K) have not been able to conceive. When you do a review of systems and brief history, you note that this man has had chronic respiratory problems typified by inability to clear his airways of mucous. You then proceed to do a physical examination. When you auscultate for breath sounds, you hear some crackles (rales). Both testes have descended and there do not appear to be any masses in the testes. Otherwise, your physical exam indicates that he is healthy. The patient informs you that he is able to achieve and maintain an erection. Moreover, he believes that his ejaculation is normal. To gather additional information that might explain a possible fertility problem in this young man, you obtain blood and ask that he provide you with a semen sample. The results of the blood work are presented in the accompanying table. When his semen was analyzed, it was found to have a normal number of sperm per milliliter. However, the laboratory report commented that more than 50% of the sperm had motility problems. You are asked by the chief of the urology service to investigate if there might be any connection between this young man's respiratory problems and his apparent infertility. Table; Blood work analysis Patient Normal range LH (mIU/m1) 20 6-23 FSH (rnIU/m1) 18 4-25 Testosterone (ngidL) 900 300-1,100 Total T4 (pgicIL) 10 5-12 Hb (g/dL) 15 13.5-17.5 What is the most likely option for this couple in terms of in vitro fertilization?
- A.
Artificial insemination using the husband's sperm and oocytes from Mrs. K
- B.
Artificial insemination using the husband's sperm and oocytes from a female other than Mrs. K
- C.
Artificial insemination using sperm from a male other than Mr. K and oocytes from Mrs. K
- D.
Intracytoplasmic sperm injection using Mr. K's sperm
Correct Answer
D. Intracytoplasmic sperm injection using Mr. K's spermExplanation
Based on the information provided, the most likely option for this couple in terms of in vitro fertilization is intracytoplasmic sperm injection using Mr. K's sperm. This is because the semen analysis showed that more than 50% of the sperm had motility problems, indicating a potential issue with the sperm's ability to fertilize an egg naturally. Intracytoplasmic sperm injection involves directly injecting a single sperm into an egg to achieve fertilization. This method would bypass any potential motility issues and increase the chances of successful fertilization.Rate this question:
-
- 7.
What are the molecular machinery (i.e. proteins) responsible for motility of mature sperm?
- A.
Skeletal muscle type of actin and myosin
- B.
Smooth muscle type of actin and myosin
- C.
Dynein and microtubules
- D.
Actin and microtubules
- E.
Myosin and microtubules
Correct Answer
C. Dynein and microtubulesExplanation
Dynein and microtubules are the molecular machinery responsible for the motility of mature sperm. Dynein is a motor protein that moves along microtubules, causing them to slide past each other and generate the force needed for movement. Microtubules, on the other hand, are cylindrical structures made up of tubulin proteins that provide structural support and serve as tracks for dynein to move along. Together, dynein and microtubules play a crucial role in the flagellar movement of sperm, allowing them to swim and reach the egg for fertilization.Rate this question:
-
- 8.
A lesbian couple asks you whether you can make them a baby with two mothers by fusing two oocytes. What should you tell them?
- A.
No problem, this can be done without a risk of major complications
- B.
Can be done, but there is an increased risk of neurological abnormalities and mental retardation in the child
- C.
This is technically possible but it is not a medically approved procedure, so I cannot do this
- D.
This should not be attempted because there is a high risk of aneuploidy
- E.
Sorry, can't be done because of imprinting
Correct Answer
E. Sorry, can't be done because of imprinting -
- 9.
During the fertilization process, what specific mechanism is responsible for polysperrny block?
- A.
Hardening of the zona pellucida
- B.
Loss of the corona radiate
- C.
Inhibition of sperm mitochondria
- D.
Formation of male pronucleus
- E.
Formation of the female pronucleus
Correct Answer
A. Hardening of the zona pellucidaExplanation
The hardening of the zona pellucida is responsible for polyspermy block during fertilization. The zona pellucida is a protective layer surrounding the oocyte. After the entry of the first sperm, the zona pellucida undergoes a process called cortical reaction, which involves the hardening of the zona pellucida. This hardening prevents any additional sperm from entering the oocyte, ensuring that only one sperm fertilizes the egg and avoids the formation of polyploid embryos.Rate this question:
-
- 10.
In-vitro fertilization requires the induction of superovulation by means of hormone treatment. Which of the following is most suitable for the induction of superovulation?
- A.
FSH
- B.
An androgen antagonist
- C.
Prednisone (a synthetic glucocorticoid)
- D.
Progesterone
- E.
A nonselective COX inhibitor
Correct Answer
A. FSHExplanation
FSH (follicle-stimulating hormone) is the most suitable for the induction of superovulation in in-vitro fertilization. FSH stimulates the growth and development of multiple follicles in the ovaries, which increases the chances of successful fertilization and implantation. This hormone treatment helps to increase the number of eggs produced, improving the success rate of IVF procedures. An androgen antagonist, prednisone, progesterone, and a nonselective COX inhibitor are not typically used for superovulation induction in IVF.Rate this question:
-
- 11.
During pregnancy, the uterine smooth muscle is quiescent. As a result, forceful uterine contractions do not occur until the ninth month of pregnancy. What explains the quiescence of uterine smooth muscle during gestation?
- A.
Oxytocin inhibits contraction of uterine smooth muscle
- B.
Low levels of blood flow to uterine smooth muscle
- C.
Prostaglandins such as prostaglandin E2 (PGE2) inhibit contraction of uterine smooth muscle,
- D.
High levels of progesterone suppress contractile activity of uterine smooth muscle.
- E.
Absence of luteinizing hormone (LH) receptors until the ninth month of pregnancy.
Correct Answer
D. High levels of progesterone suppress contractile activity of uterine smooth muscle.Explanation
High levels of progesterone suppress contractile activity of uterine smooth muscle. Progesterone is a hormone that is produced in large amounts during pregnancy. It acts as a muscle relaxant and inhibits the contraction of the uterine smooth muscle. This helps to maintain the quiescence of the uterus and prevent premature contractions. As progesterone levels decrease towards the end of pregnancy, the uterus becomes more sensitive to other hormones, such as oxytocin, which can then stimulate contractions.Rate this question:
-
- 12.
Which of the following statements about amniotic fluid is INCORRECT?
- A.
Amniotic fluid is primarily derived from maternal blood
- B.
A reduced volume of amniotic fluid is called Oligohydramnios
- C.
The fetus contributes urine to the amniotic fluid
- D.
Amniotic fluid contains nutrients and is the main nutritional support for the fetus
- E.
The fetus swallows its own amniotic fluid which is important for maintaining the correct volume of fluid in the amnion
Correct Answer
D. Amniotic fluid contains nutrients and is the main nutritional support for the fetusExplanation
Amniotic fluid is primarily derived from maternal blood, but it also includes contributions from the fetus. A reduced volume of amniotic fluid is indeed called Oligohydramnios. The fetus contributes urine to the amniotic fluid, and it swallows its own amniotic fluid to maintain the correct volume of fluid in the amnion. However, amniotic fluid does not contain nutrients and is not the main nutritional support for the fetus. The fetus receives its nutrients through the placenta.Rate this question:
-
- 13.
After the twentieth week of gestation, a thinned vasculosyncytial placental membrane is formed consisting of the following three layers:
- A.
Syncytiotrophoblast - cytotrophoblast - fetal capillary endothelium
- B.
Maternal capillary endothelium - syncytiotrophoblast - fetal capillary epithelium
- C.
Syncytiotrophoblast - connective tissue of the villus - fetal capillary endothelium
- D.
Connective tissue of the villus - syncytiotrophoblast - maternal capillary endothelium
- E.
Maternal capillary endothelium - syncytiotrophoblast - cytotrophoblasy
Correct Answer
C. Syncytiotrophoblast - connective tissue of the villus - fetal capillary endotheliumExplanation
After the twentieth week of gestation, the placental membrane is thinned and consists of three layers: syncytiotrophoblast, connective tissue of the villus, and fetal capillary endothelium. This arrangement allows for efficient exchange of nutrients and waste products between the maternal and fetal circulations. The syncytiotrophoblast layer is responsible for nutrient transfer, while the connective tissue of the villus provides structural support. The fetal capillary endothelium allows for the exchange of gases and other molecules. This arrangement ensures the proper development and nourishment of the fetus during pregnancy.Rate this question:
-
- 14.
Ectopia cordis or Pentalogy of Cantrell is a congenital malformation of the anterior body wall that includes a defect of the lower sternum, a deficient anterior diaphragm, and a heart that lies outside the chest. This condition is primarily a defect in what embryological process?
- A.
Formation of the intraembryonic coelom
- B.
Lateral folding
- C.
Formation of the intermediate mesoderm
- D.
Longitudinal folding
- E.
Formation of the head fold
Correct Answer
B. Lateral foldingExplanation
Lateral folding is the correct answer because ectopia cordis or Pentalogy of Cantrell is a congenital malformation of the anterior body wall, which is formed during the process of lateral folding in embryonic development. Lateral folding involves the folding of the embryo's sides towards the midline, which results in the formation of the body wall and the positioning of organs within it. In the case of ectopia cordis, the defect in lateral folding leads to the heart being located outside the chest.Rate this question:
-
- 15.
A 20-year-old female college student complains of breakthrough bleeding 3 months after starting to use a low-dose combined oral contraceptive regimen. Her physician questions her carefully about her pill-taking habits, and is satisfied that the patient has been taking the pills on a regular basis. Which of the following might be the most reasonable next step for this patient to continue to sustain reliable contraception with minimal adverse events?
- A.
Switch to a progestin-only mini-pill
- B.
Switch to a depot progesterone method
- C.
Switch to a combined OC with a different E component
- D.
Switch to a combined OC with a higher dose E component
- E.
SWitch to a combined OC with a higher dose P component
Correct Answer
D. Switch to a combined OC with a higher dose E componentExplanation
The most reasonable next step for this patient to continue to sustain reliable contraception with minimal adverse events would be to switch to a combined oral contraceptive (OC) with a higher dose of the estrogen (E) component. Breakthrough bleeding is a common side effect of low-dose combined OCs, and increasing the dose of estrogen can help to reduce this side effect. Switching to a progestin-only mini-pill or a depot progesterone method may not be as effective in preventing breakthrough bleeding. Switching to a combined OC with a different E component or a higher dose of the progestin (P) component may not address the issue of breakthrough bleeding.Rate this question:
-
- 16.
A 25-year-oId woman is conferring with her gynecologist regarding treatment options for debilitating endometriosis. She wishes to have children in the future and hopes to get her endometriosis under control without further compromising her fertility. They decide to try depot injections of leuprolide for the next 6 months and then re-evaluate the condition. In addition, the physician prescribes a low dose combined oral contraceptive preparation. What is the most likely reason for adding the low-dose OC?
- A.
To prevent pregnancy during exposure to leuprolide
- B.
To prevent bone loss
- C.
To maintain normal menstrual periods
- D.
To maintain body weight
- E.
To prevent hypotension
Correct Answer
B. To prevent bone lossExplanation
The most likely reason for adding the low-dose oral contraceptive (OC) is to prevent bone loss. Leuprolide, a gonadotropin-releasing hormone agonist, can cause a decrease in estrogen levels, which can lead to bone loss. The low-dose OC contains estrogen and progestin, which can help maintain bone density and prevent osteoporosis. Additionally, the OC can also help regulate menstrual periods and prevent pregnancy during the treatment with leuprolide. However, the primary reason for adding the OC in this case is to prevent bone loss.Rate this question:
-
- 17.
For a woman in the 14th week of pregnancy, which of the following substances is the LEAST likely to cross the placenta from the mother's blood into the fetal circulation?
- A.
Estradiol
- B.
Glucose
- C.
Carbon dioxide
- D.
Androstenedione
- E.
Insulin
Correct Answer
E. InsulinExplanation
Insulin is the least likely substance to cross the placenta from the mother's blood into the fetal circulation. Insulin is a large protein molecule that cannot easily pass through the placental barrier. The placenta selectively allows certain substances to pass through, such as glucose, carbon dioxide, and some hormones. However, larger molecules like insulin are generally unable to cross the placenta and reach the fetus.Rate this question:
-
- 18.
Which of the following is characteristic of the stratum basale?
- A.
Contains cells that are highly responsive to progesterone
- B.
Includes the uterine surface epithelium
- C.
Contains coiled arteries
- D.
Is the layer that undergoes shedding
- E.
Contains cells that replace the surface epithelium after menstruation
Correct Answer
E. Contains cells that replace the surface epithelium after menstruationExplanation
The stratum basale is the deepest layer of the epidermis and is responsible for regenerating new skin cells. After menstruation, the surface epithelium of the uterus is shed and the cells in the stratum basale replace it by dividing and differentiating into new epithelial cells. Therefore, the statement "Contains cells that replace the surface epithelium after menstruation" is characteristic of the stratum basale.Rate this question:
-
Back to top