Molecular Pathology

Question 1

RNA Polymerase I creates:

Answer 1

ribosomal RNA (rRNA)

Question 2

RNA Polymerase II creates:

Answer 2

messenger RNA (mRNA) and microRNA (miRNA)

Question 3

RNA Polymerase III creates:

Answer 3

transfer RNA (tRNA)

Question 4

How many genes are in the mitochondrial genome?

Answer 4

37

Question 5

Homoplasmy

Answer 5

when all mitochondria in a cell are genetically identical

Question 6

Heteroplasmy

Answer 6

when there is genetic heterogeneity within mitochondria (due to mutations and uneven distribution of the mitochondria following mitochondrial division)

Question 7

What is the cause of variable penetrance in mitochondrial genetic disorders?

Answer 7

Heteroplasmy

Question 8

Epigenetics:

What does methylation do?

Answer 8

methylation in CpG islands decreases DNA transcription of adjacent genes

Question 9

Epigenetics:

What does acetylation do?

Answer 9

acetylation “loosens” the DNA and increases transcription

Question 10

Mutation vs polymorphism

Answer 10

Mutation: genetic change, often with a potential deleterious effect
Polymorphism: not deleterious, present in at least 1% of population

Question 11

Longest chromosome

Answer 11

Chromosome 1

Question 12

Shortest chromosome

Answer 12

Chromosome 21 (but in general the higher number corresponds to shortest chromosome)

Question 13

p arm vs q arm

Answer 13

p (petit) = short arm

q = long arm

Question 14

metacentric

Answer 14

centrally located centromere

Question 15

submetacentric

Answer 15

have a p arm and a q arm

Question 16

acrocentric

Answer 16

virtually no p arm. the short areas in place of parms encode the majority of rRNA and are frequent sites of translocations

Question 17

Giemsa (G Banding) stains which nucleotide areas more?

Answer 17

A-T rich areas