Cytogenetics

Question 1

1. G-banding refers to the technique of staining chromosomes:
   a. To isolate those in the G group (i.e., chromosomes 21
   and 22)
   b. In the G0 or resting stage
   c. Using Giemsa stain
   d. To emphasize areas high in guanine residues

Answer 1

c. Using Giemsa stain

Question 2

2. Which of the following compounds is used to halt mitosis
   in metaphase for chromosome analyses?
   a. Imatinib
   b. Fluorescein
   c. Trypsin
   d. Colchicine

Answer 2

d. Colchicine

Question 3

3. One arm of a chromosome has 30 bands. Which band
   would be nearest the centromere?
   a. Band 1
   b. Band 15
   c. Band 30

Answer 3

a. Band 1

Question 4

4. Which of the following is not an advantage of the use of FISH?
   a. It can be used on nondividing cells.
   b. It can be used on paraffin-embedded tissue.
   c. It can detect mutations that do not result in abnormal
   banding patterns.
   d. It must be performed on dividing cells.

Answer 4

d. It must be performed on dividing cells.

Question 5

5. Which of the following types of mutations would likely not
   be detectable with cytogenetic banding techniques?
   a. Point mutation resulting in a single amino acid substitution
   b. Transfer of genetic material from one chromosome to
   another
   c. Loss of genetic material from a chromosome that does
   not appear on any other chromosome
   d. Duplication of a chromosome resulting in 3n of that
   genetic material

Answer 5

a. Point mutation resulting in a single amino acid substitution

Question 6

6. Which of the following describes a chromosomal deletion?
   a. Point mutation resulting in a single amino acid substitution
   b. Transfer of genetic material from one chromosome to
   another
   c. Loss of genetic material from a chromosome that does
   not appear on any other chromosome
   d. Duplication of a chromosome resulting in 3n of that
   genetic material

Answer 6

c. Loss of genetic material from a chromosome that does
not appear on any other chromosome

Question 7

The chromosome analysis performed on a patient’s leukemic cells is reported as 47, XY,14,del(5)(q31)[20]. Answer
questions 7 to 9 based on this description.

7. This patient’s cells have which of the following mutations?
   a. Loss of the entire number 31 chromosome
   b. Loss of the entire number 5 chromosome
   c. Loss of a portion of the short arm of chromosome 4
   d. Loss of a portion of the long arm of chromosome 5

Answer 7

d. Loss of a portion of the long arm of chromosome 5

Question 8

The chromosome analysis performed on a patient’s leukemic cells is reported as 47, XY,14,del(5)(q31)[20]. Answer
questions 7 to 9 based on this description.

8. What other mutation is present in this patient’s cells?
   a. Polyploidy
   b. Tetraploidy
   c. An extra chromosome 4
   d. Four copies of chromosome 5

Answer 8

c. An extra chromosome 4

Question 9

The chromosome analysis performed on a patient’s leukemic cells is reported as 47, XY,14,del(5)(q31)[20]. Answer
questions 7 to 9 based on this description.

9. This patient’s leukemic cells demonstrate:
   a. Structural chromosomal defects only
   b. Numeric chromosomal defects only
   c. Both structural and numeric chromosomal defects

Answer 9

c. Both structural and numeric chromosomal defect

Question 10

10. Aneuploidy describes the total chromosome number:
    a. That is a multiple of the haploid number
    b. That reflects a loss or gain of a single chromosome
    c. That is diploid but has a balanced deletion and duplication of whole chromosomes
    d. In gametes; diploid is the number in somatic cells

Answer 10

b. That reflects a loss or gain of a single chromosome