1.
Dr. Larsen
In the last century, several countries instituted policies where sterilization was forced on, for example, people with mental retardation. In addition to this being ethically questionable, one of the reasons it was also wrong is because:
Correct Answer
B. Most of the cases caused by dominant diseases come from new mutations
Explanation
Forced sterilization policies based on mental retardation were ethically questionable because most cases caused by dominant diseases come from new mutations. This means that sterilizing individuals with mental retardation would not have prevented the transmission of these diseases to future generations, as the mutations causing them were not inherited.
2.
Imagine a species of Giraffe living on the savanna in Africa. The overall size of these varies as expected for a quantitative trait. The smallest giraffes have difficulty surviving, because they cannot reach the leaves on the trees that this species feed on. The largest giraffes have difficulty growing muscles large enough to move the massive bones needed for supporting this size of an animal. Therefore, the giraffes closest to the average size stand the best chance of surviving and reproducing. This is an example of which special concept?
Correct Answer
C. Stabilizing selection
Explanation
Stabilizing selection is the correct answer because it describes a type of natural selection where individuals with average or intermediate traits have a higher fitness compared to individuals with extreme traits. In this scenario, the giraffes closest to the average size have the best chance of survival and reproduction, while the smallest and largest giraffes face difficulties. This leads to a stabilizing effect on the population, maintaining the average size as the most advantageous trait.
3.
A syndrome is known to cause excessive height, reduced IQ, and the cells exhibit 1 Barr body. Which karyotype is most compatible with the above description?
Correct Answer
D. 47XXY
Explanation
The correct answer is 47XXY. This karyotype is most compatible with the given description because it is associated with a syndrome known as Klinefelter syndrome. Individuals with Klinefelter syndrome typically have excessive height, reduced IQ, and exhibit 1 Barr body. The presence of an extra X chromosome (XXY) is characteristic of this syndrome.
4.
Your patient has Down syndrome. Talking with the parents, they ask you: what is the risk that we would have a child with Down syndrome if we have another child? Your best estimate of the risk is:
Correct Answer
D. 1-2 %
Explanation
The correct answer is 1-2%. Down syndrome is caused by the presence of an extra copy of chromosome 21. The risk of having a child with Down syndrome increases with the mother's age, but overall, the risk is relatively low. The estimated risk of having another child with Down syndrome for parents who already have one child with Down syndrome is around 1-2%.
5.
Dr. Blanchetot
Neurobibromatosis type 1 (NF1) is inherited as an autosomal dominant condition. The cardinal features are café au lait spots, small soft fleshy growth known as neurofibromata and Lisch nodules in the iris. NF1 is caused by mutations of a gene termed neurofibromin located on chromosome 17. Loss of heterozygosity for markers for chromosome 17 markers has been observed in small benign neurofibromata. This feature is an indication that
Correct Answer
B. The gene responsible is showing recessive inheritance at cellular level
Explanation
The correct answer is that the gene responsible is showing recessive inheritance at the cellular level. This is indicated by the loss of heterozygosity for markers on chromosome 17 in small benign neurofibromata. This suggests that both copies of the gene need to be mutated for the condition to manifest, indicating a recessive inheritance pattern at the cellular level.
6.
Martha, 31, comes to a genetic clinic on a referral from her family physician. The family history (see below) reveals several individuals with colon cancer on her mother’s side. Martha’s mother died in an accident at the age of 38 and was known to be healthy. Martha explains that she is fine and she has been not diagnosed with any health problem and she considers herself unlikely to be at risk of any problem
What is the most appropriate statement that the physician will provide to Martha?
Correct Answer
C. Her 60-year old maternal uncle (III-4) should have a colonoscopy
Explanation
Based on the family history of colon cancer on Martha's mother's side, the most appropriate statement that the physician will provide to Martha is that her 60-year old maternal uncle (III-4) should have a colonoscopy. This is because Martha's mother died at a young age and there is a high frequency of colon cancer in the family, indicating a potential genetic risk. Therefore, it is important for Martha's uncle to undergo a colonoscopy to screen for any signs of colon cancer and to assess the risk for other family members, including Martha herself.
7.
Dr. Kalliecharan
Which of the following statements is characteristic of the ovary?
Correct Answer
A. The theca interna secretes androstenedione in response to LH
Explanation
Zona pellucida
During the primary follicle stage, an amorphous substance appears, separating the oocyte from the follicular cells.
Contains specific proteins (ZP1, ZP2, ZP3) secreted by the oocyte and form an extracellular coat of glycoproteins.
ZP-3 is most important; acts as receptors for sperm binding and for inducing the acrosomal reaction.
Theca interna, theca externa, and granulosa cells
Stromal cells around the multilaminar primary follicle (theca folliculi) forms an inner theca interna (richly vascularized cellular layer), and an outer theca externa (fibrous c.t.)
Theca interna cells: steroid-producing cells, possess LH receptors on their cell membrane; produce androstenedione (male sex hormone), which enters the granulosa cells where it is converted by the enzyme aromatase into the estrogen estradiol.
Granulosa cells and theca interna are separated by a thickened basal lamina.
Theca EXTERNA do not really secrete hormones (atleast no well known ones)
(Slide 22 Female-Repro-Yin)
8.
Which of the following gonadotropins is correctly associated with the structures in the ovary?
Correct Answer
D. FSH stimulates proliferation of the follicular cells in the granulosa layer of the secondary follicle
Explanation
3) Secondary/ Antral folliclesCharacterized by the accumulations of fluid known as liquor folliculi among the granulosa cells; proliferation of granulosa cells depends on FSH, and they possess FSH receptors; FSH (along with estrogen) induces the granulosa cells to express LH receptors.
9.
Which of the following is characteristic of the stratum basale?
Correct Answer
C. It contains cells that form the surface epithelium after menstruation
10.
Dr. Yin
The uterus is formed from
Correct Answer
D. Caudal part of paramesonepHric ducts
Explanation
The correct answer is the caudal part of the paramesonephric ducts. The paramesonephric ducts, also known as Müllerian ducts, are bilateral structures that develop in the early embryo and give rise to the female reproductive system. The caudal part of these ducts specifically develops into the uterus, cervix, and upper part of the vagina. The sinovaginal bulbs, pelvic part of the primitive urogenital sinus, caudal part of the mesonephric ducts, and sinus tubercle are not involved in the formation of the uterus.
11.
An infant presents with a ball-like structure on her “bottom” (see image below). The ball-like structure indicated by the pointer is homologous to:
Correct Answer
C. Seminal colliculus
Explanation
The image shows a ball-like structure on the infant's "bottom." The seminal colliculus is a small elevation found in the posterior urethra of males. It is responsible for the opening of the ejaculatory ducts and the prostatic utricle. The other options, such as paradidymis, appendix testis, scrotum, and prostatic utricle, are not homologous to the ball-like structure seen in the image. Therefore, the correct answer is the seminal colliculus.
12.
Dr. St. Hilaire
Klinefelter’s Syndrome is a disorder that results from nondisjunction of XX homologues during meiosis. In which of the following spermatogenic cells would this most likely occur?
Correct Answer
B. Primary spermatocytes
Explanation
Type B spermatogonia will undergo MITOSIS to become primary spermatocytes.
Primary spermatocytes will then undergo MEIOSIS I.
(slilde 12 thompson)
13.
A 65-year-old man complains of trouble urinating. Physical exam and further tests show an enlarged prostate but no evidence of cancerous cells. A diagnosis of benign prostatic hyperplasia (BpH) was made. In which region of the prostate gland is this condition most likely to occur?
Correct Answer
A. Transition zone
Explanation
Benign prostatic hyperplasia (BPH) is a condition characterized by the enlargement of the prostate gland. This enlargement typically occurs in the transition zone of the prostate gland. The transition zone is the area of the prostate gland that surrounds the urethra. As the prostate gland enlarges in this region, it can compress the urethra, leading to symptoms such as trouble urinating. Therefore, in a 65-year-old man presenting with trouble urinating and an enlarged prostate without evidence of cancer, BPH is most likely to occur in the transition zone of the prostate gland.
14.
Dr. Thomas
Which of the following potential drug targets would provide the most appropriate treatment for a man with androgen-dependent testicular cancer and hormone-dependent metastases?
Correct Answer
B. GnRH receptors
Explanation
GnRH receptors would provide the most appropriate treatment for a man with androgen-dependent testicular cancer and hormone-dependent metastases. GnRH (gonadotropin-releasing hormone) is responsible for the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland, which in turn stimulates the production of testosterone in the testes. By targeting the GnRH receptors, the production of testosterone can be suppressed, which is important in the treatment of androgen-dependent testicular cancer. This would help in controlling the growth and spread of the cancer cells.
15.
A 36-year-old woman requests a prescription from her gynecologist for oral contraceptives. She is married, has two children, 4 and 6 years of age, and works in a factory where she stands all day. She smokes cigarettes on a regular basis and drinks moderately on weekends. She is 5’6” tall and weighs 185lbs. Her physical exam is otherwise unremarkable. Which of the above features of her history and physical most likely will keep her physician from prescribing combined oral contraceptives for this patient?
Correct Answer
A. Her cigarette smoking
Explanation
Adverse effects of OCs
Thrombotic events
- Higher doses of E increase production of clotting factors; progestin component can also influence clotting factor effect
- Lower dose, modern pills don’t seem to have a clinical effect on these factors
- Smoking produces a shift to hypercoagulability
Combination OCs are absolutely contraindicated in smokers over 35 years old
Population Incidence (no. per 100,000/year)
Overall[69] 5
WOMEN YOUNGER THAN 35 YEARS
Nonsmokers 4
Nonsmokers taking OCs 4
Smokers 8
Smokers taking OCs 43
WOMEN 35 YEARS AND OLDER
Nonsmokers 10
Nonsmokers taking OCs 40
Smokers 88
Smokers taking OCs 485
16.
Dr. Wright
A male visited his family doctor because he had no facial hair and significant development of breast tissue. This was tentatively diagnosed as gynecomastia. A physical exam revealed that he was overweight (190% of normal weight for his height). Overproduction of what hormone was most likely responsible for the gynecomastia?
Correct Answer
E. Estradiol
Explanation
Gynecomastia is the development of breast tissue in males, which can be caused by an imbalance of hormones. Estradiol is a form of estrogen, a female hormone, and its overproduction in males can lead to the development of breast tissue. Testosterone is a male hormone and its deficiency can also cause gynecomastia, but in this case, the question mentions that the patient had no facial hair, which suggests a normal level of testosterone. Therefore, the most likely hormone responsible for the gynecomastia in this case is estradiol.
17.
In the menstrual cycle, there are two separate negative feedbacks and one positive feedback, depending on the point in the cycle. In a normal 28 day cycle, on day 12, what feedback loop is active?
Correct Answer
C. Estradiol-dependent negative feedback
Explanation
On day 12 of a normal 28-day menstrual cycle, the feedback loop that is active is the Estradiol-dependent negative feedback. This means that the hormone estradiol, which is produced by the developing follicles in the ovaries, inhibits the release of follicle-stimulating hormone (FSH) from the pituitary gland. This negative feedback helps regulate the levels of FSH and prevents the development of multiple follicles at the same time.
18.
A 48-year-old female complains that for the past 6 months she has had episodes in which her face and neck have become hot and red. She has been amenorrheic for the past 7 months and her home pregnancy test was negative. However, prior to this her menstrual history was normal. Circulating levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), human chorionic gonadotropin (hCG), progesterone, and estradiol were measured. What would be the predicted results?
Correct Answer
A. 1
Explanation
The predicted results would show elevated levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH) due to the patient's amenorrhea and negative pregnancy test. This suggests that the patient may be experiencing menopausal symptoms and has entered perimenopause or menopause. The elevated FSH and LH levels indicate that the body is trying to stimulate the ovaries to produce eggs, but they are not responding. This is a common hormonal pattern seen in menopause.
19.
Dr. Barremkala
A 30-year-old gymnast is admitted to the E.R. after a fall from the high bar while he was practicing his routine. He complains of lower back pain and paresthesia into the lower extremities. The CT scan shows a fracture of the L2 vertebra with compression of the spinal cord. A neurologist confirms the destruction of the sacral segments of the spinal cord. Which of the following is the most likely finding you will see in this patient?
Correct Answer
E. Inability to achieve erection
Explanation
The most likely finding in this patient is the inability to achieve an erection. The patient's symptoms, including lower back pain, paresthesia into the lower extremities, and destruction of the sacral segments of the spinal cord, suggest damage to the nerves responsible for sexual function. The sacral segments of the spinal cord are involved in innervating the genitalia and controlling sexual function, including achieving an erection. Therefore, it is likely that the patient will experience difficulty or inability to achieve an erection as a result of the spinal cord injury.
20.
A 48-year-old women presents to you with a swelling in her left labia majora associated with pain. Given of the location of the swelling, you diagnosis it as Bartholinitis. Which group of lymph nodes will you examine for the signs of inflammation?
Correct Answer
A. Superficial inguinal
Explanation
When a patient presents with a swelling in the left labia majora associated with pain, the most likely diagnosis is Bartholinitis, which is inflammation of the Bartholin's glands. The Bartholin's glands are located in the labia majora and drain into the vestibule of the vagina. The lymphatic drainage from the labia majora goes to the superficial inguinal lymph nodes. Therefore, to examine for signs of inflammation, the superficial inguinal lymph nodes should be examined.
21.
Riley–Day syndrome is a disorder of the autonomic nervous system which affects the development and survival of sensory, sympathetic and some parasympathetic neurons in the autonomic and sensory nervous system resulting in variable symptoms including: insensitivity to pain, labile blood pressure, ataxia and feeding difficulties. This syndrome will most likely affect which of the following structures?
Correct Answer
D. Internal urethral spHincter
Explanation
Riley-Day syndrome affects the autonomic nervous system, which controls involuntary bodily functions. The internal urethral sphincter is a part of the autonomic nervous system and is responsible for controlling the flow of urine. Therefore, it is likely to be affected by Riley-Day syndrome. The other structures mentioned in the options, such as the pelvic diaphragm, external anal sphincter, and external urethral sphincter, are not directly related to the autonomic nervous system and are less likely to be affected by this syndrome.
22.
A 53-year-old woman is concerned as she has discomfort and difficulty during micturition. On vaginal examination, you see a protrusion from the anterior wall of the vaginal orifice. What is the most likely diagnosis?
Correct Answer
B. Cystocele
Explanation
A cystocele is the most likely diagnosis in this case. A cystocele occurs when the supportive tissues between a woman's bladder and vaginal wall weaken, causing the bladder to bulge into the vagina. This can result in discomfort and difficulty during urination, as well as a protrusion from the anterior wall of the vaginal orifice, which is seen on vaginal examination. Hydrocele, rectocele, varicocele, and cremnocele are not associated with these symptoms or findings.
23.
Dr. Dhiman
During surgery to treat an ischioanal abscess, the inferior rectal nerve is damaged. This nerve is a direct branch of which of the following nerves?
Correct Answer
A. Pudendal nerve
Explanation
During surgery to treat an ischioanal abscess, the inferior rectal nerve is damaged. The inferior rectal nerve supplies sensory innervation to the anal canal and perianal region. It is a direct branch of the pudendal nerve, which is responsible for innervating the external genitalia, perineum, and anal region. Therefore, damage to the inferior rectal nerve suggests injury to the pudendal nerve.