Site MapHelpFeedbackQuiz for Practitioners
Quiz for Practitioners
(See related pages)



1

In spermatogenesis, at which stage do the sex chromosomes segregate?
A)Meiosis II, primary spermatocyte
B)Meiosis I, primary spermatocyte
C)Meiosis II, secondary spermatocyte
D)Meiosis I, secondary spermatocyte
E)Meiosis II, spermatid
2

In contrast to spermatogenesis, oogenesis is largely completed prior to birth. The ova develop from oogonia, which are cells derived from the ovarian cortical tissue. By the third month of gestation, the primary oocyte begins to develop. At which stage of cell division are the oocytes suspended prior to ovulation?
A)First metaphase
B)Second metaphase
C)First prophase
D)Second prophase
E)Second telophase
3

A neonate is found to have an enzymatic deficiency in the conversion of pyruvate to pyruvate phosphate. The wild-type sequence includes the following:

Lys-Arg-His-His-Tyr-Leu
AAG-AAG-CAC-CAC-UAC-CUC

The sequence of the mutated enzyme is

Lys-Glu-Ala-Pro-Leu-Pro
AAG-GAA-GCA-CCA-CUA-CCU

What kind of mutation is illustrated by the above amino acid sequence?
A)Point mutation
B)Frame shift mutation resulting in a nucleotide deletion
C)Chain termination mutation
D)Frame shift mutation resulting in the addition of a nucleotide
E)Splice mutation
4

Bob arrives in your office for genetic counseling. Bob's brother Tom died at a young age from Tay-Sachs disease. Both he and his sister Sarah are unaffected. Bob's son Adam and Sarah's daughter Jennifer have recently married and are expecting their first child. What is the chance that the child would have Tay-Sachs disease?
A)1/4
B)1/9
C)1/12
D)1/36
E)1/44
5

How many genes are deleted in hemoglobin H disease?
A)UNDEFINED: ANSWERTEXT
B)1
C)2
D)3
E)4
6

You are called to see a 23-year-old woman who is suffering from a moderately severe postpartum hemorrhage. She has no other significant medical conditions. On physical examination there is no evidence of any other significant bleeding diatheses. There are no petechial lesions or ecchymoses noted, and there is no bleeding within the oral pharynx. Her past medical history includes a wisdom tooth extraction that was complicated by a severe hemorrhage. In addition, she has had a prior hemarthrosis of her right knee after moderate trauma. Both of her parents are alive and well and neither has a significant bleeding history. Her father had a recent uncomplicated inguinal hernia repair, and her mother had a recent uncomplicated breast biopsy for a benign lesion. Her menses are of normal frequency and duration, but she does complain of heavy menstrual bleeding. All laboratory data are pending. Her brother is 18 years old and has had multiple spontaneous hemarthroses without evidence of trauma. He has also had an episode of a spontaneous psoas hematoma. What is the most likely explanation for this patient's bleeding disorder?
A)von Willebrand's disease
B)Factor XI deficiency
C)Glanzmann's thrombasthenia
D)Hemophilia A
E)Dysfibrinogenemia
7

A 16-year-old adolescent is seen in your clinic. On physical examination you note that he has small testes for his stated age and has poorly developed secondary sexual characteristics. In addition, on physical examination there is notable gynecomastia. He is rather tall, with abnormally long upper and lower limbs. A buccal smear is obtained and examined microscopically. How many chromatin-positive inclusion bodies are seen?
A)UNDEFINED: ANSWERTEXT
B)1
C)2
D)3
E)4
8

A 3-month-old child arrives in your clinic who has profound hypotonia. On physical examination, in addition to the hypotonia, he is noted to have a brachycephalic head with a flat occiput and a low bridge nasal structure. The hands are short and broad, and a single crease is noted on the fifth finger. The feet show a characteristic wide gap between the first and second toes and the furrow is extending along the proximal plantar surface. A full karyotype is performed and shows an abnormality. However, the total number of chromosomes is normal at 46. What is the most likely explanation for this child's clinical syndrome?
A)Fragile X syndrome
B)Down's syndrome
C)Prader-Willi syndrome
D)Cri-du-chat syndrome
E)Isochromosome X
9

Which of the following is an example of a balanced karyotype?
A)46, X, i(Xq)
B)46, X, X, -14, +t(14;21) (p11;q11)
C)46X, Y, -5, +der5 (5;11) (q21;q21) mat
D)46, X, Y, +t(9;22) (q34;q11.2)
E)46, X, -X, +t(X;21) (p21;p12)
10

A patient has blood type AB. She has a sister with blood type O, the father has blood type A, and the mother, blood type O. The maternal grandparents were first-degree cousins. What is the most likely explanation for this patient's blood type?
A)There is a question of paternity
B)An error was made in the typing of the patient's blood type
C)The patient's mother's serum contains anti-A, anti-B, and anti-H antibodies
D)An error in the typing occurred in the mother's blood type
E)A new mutation in the patient occurred, giving rise to the AB blood phenotype
11

A male child presents to your clinic with a history of multiple pulmonary infections. The child's birth was complicated by meconium ileus. The child has had a recurrent cough with thick, difficult-to-mobilize, viscous sputum. There have been multiple episodes of recurrent pulmonary infections and abnormal chest X-rays. The child is also thin for his stated age and seems to be failing to thrive. Which of the following statements is correct concerning the mode of inheritance of this patient's disease?
A)Most patients will have an affected parent
B)Males are more commonly affected than females
C)The recurrent risk is 1 in 4 for each subsequent sibling
D)The trait is never transmitted directly from father to son
E)The disorder is a result of a new spontaneous mutation
12

A 45-year-old man comes to your office with a history of stage I colon cancer. The patient's father was diagnosed at age 49 with colon cancer, and his brother (the patient's uncle) also had colon cancer diagnosed at age 47. The patient's grandmother had endometrial cancer diagnosed at age 51. This patient most likely has a defect in which of the following genes?
A)p53
B)APC
C)MSH-2 gene affecting DNA mismatched repair
D)Retinoblastoma gene (Rb)
E)A reciprocal translocation involving chromosomes 8 and 14, t(8;14)
13

The Prader-Willi syndrome (PWS) is a rare syndrome of progressive obesity, hypotonia, and mental retardation. On physical examination, children with PWS also have small hands and feet and male children also have cryptorchidism. Which of the following statements concerning the mode of inheritance of PWS is true?
A)PWS is inherited as an X-linked recessive disorder
B)PWS is inherited as an X-linked dominant disorder
C)PWS is a result of a gene duplication
D)PWS is caused by maternal uniparental disomy
E)PWS is inherited as an autosomal dominant disorder
14

Match the following statement with the disease it most aptly describes: A disease in which an affected person will bear, on average, both normal and affected offspring in equal proportion, with children of either sex equally likely to be affected, characterized by a delayed age of onset, and in which patients are >90% likely to have inherited an abnormal gene from a parent.
A)Manic-depressive psychosis
B)Myasthenia gravis
C)Hemophilia A
D)Neurofibromatosis
E)Huntington's chorea
15

Diseases inherited in a multifactorial genetic fashion (i.e., not autosomal dominant, autosomal recessive, or X-linked) and seen more frequently in persons bearing certain histocompatibility antigens include
A)gluten-sensitive enteropathy
B)neurofibromatosis
C)adult polycystic kidney disease
D)Wilson's disease
E)cystic fibrosis
16

Which of the following statements concerning patients who have Klinefelter syndrome is correct?
A)They are 20 times as likely as normal men to develop breast cancer.
B)They have normal serum testosterone and testes of average size.
C)They have an increased incidence of hypospadias.
D)The diagnosis can usually be made after birth.
E)Social maladjustment and mental deficiency is a rare finding in patients with Klinefelter syndrome.
17

Which of the following statements concerning the ataxia-telangiectasia syndrome is correct?
A)(A) It is inherited as an autosomal dominant disorder.
B)(B) The cause is adenosine deaminase deficiency.
C)(C) Malignancy is a common cause of death.
D)(D) Both the immunodeficiency and the chromosomal instability are seen primarily in homozygotes.
E)(E) Humoral and not cellular immunity seems to be primarily affected.
18

Which of the following statements concerning Marfan syndrome is true?
A)Marfan syndrome is an example of genetic heterogeneity.
B)All patients should have a slit-lamp examination.
C)The skin examination is usually unremarkable.
D)Most patients have a mutation in the gene coding for elastase.
E)This disorder is generally inherited as an autosomal recessive disorder.
19

Which of the following is true in Alport syndrome?
A)The presence of hematuria is typically benign.
B)The disorder is generally inherited as an autosomal recessive disorder.
C)Most patients have mutations in a gene coding for collagen.
D)Blue sclerae are a common finding.
E)The syndrome is characterized by the presence of profound sensorineural deafness.







Harrisons Internal MedicineOnline Learning Center

Home > 03. Genetics > Quiz for Practitioners