Question 1

What is the value of chromosome banding?

Accepted Answer

A)   The chromosomes can be visualized
B)   All chromosomes stain similarly
C)   Each chromosome has a characteristic banding pattern
D)   Genes are stained
E)   Specific DNA sequences can be visualized C

Question 2

Which of the following can be found in normal carrier individuals?

Accepted Answer

A)   Paracentric inversions
B)   Translocations
C)   Pericentric inversions
D)   Deletions
E)   All of the above E

Question 3

Why are phytohemagglutinin and then colchicine added to blood samples before chromosome analysis is done?

Accepted Answer

A)   To lyse the red blood cells
B)   To enhance the chromosomal banding patterns
C)   To stimulate the cells to divide and arrest at metaphase
D)   So that chromosomes will align nicely on mitotic spindles
E)   So that homologous chromosomes will be paired at the equatorial plane of the cell C

Question 4

Which of the following refers to the central constriction of a chromosome?

Accepted Answer

A)   Telomere
B)   Centromere
C)   Centriole
D)   Chromatid
E)   Central repeat

Question 5

The significance of a Robertsonian translocation is which of the following?

Accepted Answer

A)   The loss of the sequences in the p arms of the involved chromosomes
B)   Inability of the involved chromosomes to recombine
C)   The risk of an unbalanced chromosome complement in gametes
D)   Loss of chromosomal material in somatic cells during mitosis
E)   Robertsonian translocations are generally benign

Question 6

Due to differences in male and female meiosis,advanced paternal age effect is more likely to be associated with what type of mutation?

Accepted Answer

A)   Chromosome abnormalities
B)   Translocations
C)   De novo dominant mutations
D)   Aneuploidies
E)   Fragile sites

Question 7

Which form of chromosomal DNA stains darkly and is largely composed of unexpressed,repetitive DNA?

Accepted Answer

A)   Euchromatin
B)   5' UTRs
C)   Heterochromatin
D)   Nucleosomes
E)   Introns

Exam 3: Chromosomes and Cell Division