Lecture 23

Question 1

What percentage of human chromosomes are TEs?

Answer 1

45%

Question 2

What is the percent change that spontaneous mutations due to TE occur in humans?

Answer 2

0.2%

Question 3

What is a TE?

Answer 3

genetic element that can move and reproduce in the genome

Question 4

What happens if a TE inserts into a gene?

Answer 4

Can disrupt gene, cause a spontaneous mutation

Question 5

Where are TEs found on chromosomes?

Answer 5

in introns and intergenic DNA (everywhere except exons)

Question 6

What is the TE activity in humans and Drosophila?

Answer 6

rare in humans

common in Drosophila

Question 7

Some human TEs, such as Alu PV92, are polymorphic. What does this mean?

Answer 7

present in some people, absent in others

Question 8

Who discovered TEs? What did she do?

Answer 8

Barbara McClintock, a corn geneticist at Cold Spring Harbor Laboratory (New York)

proved that meiotic crossovers involved dsDNA breaks. discovered TEs

Question 9

TEs make how many proteins?

Answer 9

one unique protein

Question 10

How do TEs move?

Answer 10

DNA Pols and DNA repair enzymes