Lecture8

Question 1

What is mitochondrial polymerase? and from what subunits it has consist?

Answer 1

DNA polymerase gamma - The mitochondrial polymerase
• POLγA (POLG1) - catalytic subuint
• POLγB (POLG2)- accessory dimeric subunit

Question 2

What do Homoplasmy and heteroplasmy mean?

Answer 2

Homoplasmy - All copies of mtDNA are identical
Heteroplasmy - Copies of mtDNA that differ in their
nucleotide sequence are present in the same cell

Question 3

What are Mechanisms that affect the degree of heteroplasmy?

Answer 3

1) Vegetative segregation
2) Relaxed replication
3) The mtDNA genetic bottleneck

Question 4

Vegetative segregation can lead to cells receiving the same proportions of WT or mutant mtDNA.
True or False?

Answer 4

False, Vegetative segregation can lead to cells receiving different proportions of WT or mutant
mtDNA

Question 5

Mutant mtDNA is selected against on an organism or Cellular level.
True or false?

Answer 5

False, Mutant mtDNA is selected against on a genome or organelle level