ABNORMALITIES IN CHROMOSOME NUMBER AND STRUCTURE 1

Question 1

Abnormalities in chromosomes are produced by the following, EXCEPT:

A. Misrepair of broken chromosomes
B. Improper recombination
C. Erroneous segregation during cell division
D. DNA mutation

Answer 1

D

Question 2

Nondysjunction that occurs during meiosis II will NOT
result in which of the following chromosome number in the
zygote?

A. Normal
B. Monosomy
C. Nullisomy
D. Trisomy

Answer 2

C

Question 3

Meiotic nondisjunction is more commonly seen among
which of the following?

A. Increasing maternal age
B. Increasing paternal age
C. Post-radiation in the young
D. Maternal infection

Answer 3

A

Question 4

Single gene mutation is increased in which of the
following?

A. Oogenesis in elderly women
B. Spermatogenesis in elderly men
C. Both
D. Neither

Answer 4

B

Question 5

Which of the following outcome of anaphase lag is almost always not compatible with embryogenesis or
livebirth?

A. Monosomy of sex chromosomes
B. Trisomy of sex chromosomes
C. Monosomy of autosomes
D. Trisomy of autosomes

Answer 5

C

Question 6

Female with classic trisomy 21

Answer 6

47,XX,+21

Question 7

Male with terminal deletion of chromosome 3, short
arm, region 2, band 3, sub-band 1

Answer 7

46,XY,del(3)(p23.1)

Question 8

A female with monosomy X

Answer 8

45,X

Question 9

A male with triploidy

Answer 9

69,XYY OR 69,XXY

Question 10

A female with balanced reciprocal translocation with
breakpoint in the long arm of chromosome 7, region 2
band 3 and the short arm of chromosome 10, region 3
band 2 sub-band 1

Answer 10

46,XX,t(7;10)(q23)(p32.1)