CMMB MIDTERM 1 QUESTIONS Flashcards
Which are the three smallest autosomal chromosomes according to the physical size of the chromosome?
a) 21,22,Y
b) 20,21,22
c) 13,18,21
d) 18,21,Y
e) X,Y,21
B; question asked about smallest autosomes and not least number of genes.
Which of the following substrates is not appropriate for cytogenetic testing?
a) bone marrow
b) red blood cells
c) white blood cells
d) skin biospy
e) cord blood
B; all but red blood cells have DNA.
When a chromosome is stained with Giemsa, the stain tends to bind to
a) low AT regions of the chromsoosme AND low content of repetitive DNA
b) low GC regions of the chromosome AND high content of repetitive DNA
c) high AT regions of the chromosome AND low content of repetitive DNA
d) high AT regions of the chromosome AND high content of repetitive DNA
e) high GC regions of the chromosome AND low content of repetitive DNA Ch
D; in class we said high AT content and high repeat content correlate (with the exception of Alu SINEs).
Chromosome banding may be undertaken at the following stage of the cell cycle
a) interphase
b) prophase
c) all stages
d) both a & b
e) none of the above
B; banding analysis would be informative when chromosomes are condensed (ie. when there is heterochromatin for the stain to bind to). Prophase, metaphase, and prometaphase are what was mentioned on a slide.
The differences btw a short-term and long-term culture of lymphocytes is that
a) the cytogeneticist infected only the former with a virus
b) the cytogeneticist infected each culture with a different virus
c) the cytogeneticist infected only the latter with a virus
d) the cytogeneticist infected the former with bacteria and the latter with a virus
e) none of the above
C; almost 90% of students answered this correctly
Which of the following bands would be most proximal to the telomere on the short arm of a chromosome?
a) 3p13.2
b) 16q24.5
c) 3p12.3
d) 16q25.4
e) both a&d
A; the answer was not C because that band is closest to the centromere.
Which of the following experimental techniques rely on the principles of DNA complementarity?
a) CGH
b) Chromsome painting
c) FISH
d) all of the above
e) only a & c
D; recall I said that all genetic techniques are based on the principle of complementarity.
Which of the following chromsomal abnormalities would be most consistent with the results displayed in the CGH results above?
a) trisomy 17
b) monsomy 17
c) deletion of a portion of chromosome 17
d) duplication of a potion of chromosome 17
e) inversion of a portion of chromosome 17
DIAGRAM
D; had it been a deletion the grey peak would have spanned the entirety of the field.
What are the most likely sexes of the patient and the control individual?
a) patient male, control female
b) patient female, control male
c) patient male; control male
d) patient female; control female
e) impossible to tell from the data provided
A; almost 90% of students answered this correctly.
