AIPGMEE 2016 Pathology MCQ Genetics

The Cellular and Molecular Basis of Inheritance

1. Base substitutions:
a. May result in nonsense mutations
b. Can affect splicing
c. Are always pathogenic
d. Can affect gene expression
e. Result in frameshift mutations
2. Transcription:
a. Describes the production of polypeptides from the
mRNA template
b. Occurs in the nucleus
c. Produces single-stranded mRNA using the antisense
DNA strand as a template
d. Is regulated by transcription factors that bind to the
3′ UTR
e. Precedes 5′ capping and polyadenylation
3. The following are directly involved in
DNA repair:
a. Glycosylases
b. DNA polymerases
c. Ligases
d. Splicing
e. Ribosomes
4. During DNA replication:
a. DNA helicase separates the double-stranded DNA
b. DNA is synthesized in one direction
c. Okazaki fragments are synthesized
d. DNA is synthesized in a conservative manner
e. Uracil is inserted to pair with adenine
ANSWERS
1. Base substitutions:
a. True. When a stop codon replaces an amino acid
b. True. For example, by mutation of conserved splice
donor and acceptor sites
c. False. Silent mutations or substitutions in noncoding
regions may not be pathogenic
d. True. For example promoter mutations may affect
binding of transcription factors
e. False. Frameshifts are caused by the insertion or
deletion of nucleotides
2. Transcription:
a. False. During transcription mRNA is produced from
the DNA template
b. True. The mRNA product is then translocated to
the cytoplasm
c. True. The mRNA is complementary to the
antisense strand
d. False. Transcription factors bind to regulatory
sequences within the promoter
e. True. The addition of the 5′ cap and 3′ poly(A) tail
facilitates transport to the cytoplasm
3. The following are directly involved in
DNA repair:
a. True. The DNA glycosylase MYH is involved in
base excision repair (BER)
b. True. They incorporate the correct bases
c. True. They seal gaps after abnormal base excision
and correct base insertion
d. False. Splicing removes introns during mRNA
production
e. False. Ribosomes are involved in translation
4. During DNA replication:
a. True. It unwinds the DNA helix
b. False. Replication occurs in both directions
c. True. These fragments are joined by DNA ligase to
form the lagging strand
d. False. DNA replication is semiconservative as only
one strand is newly synthesized
e. False. Uracil is incorporated in mRNA, thymine
in DNA