Chapter 35: DNA Repair and Recombination (Test 1)

Question 1

What is the simplest source of DNA damage?

Answer 1

• The incorporation of an incorrect base

Question 2

What kind of DNA polymerase can replicate across damaged DNA and generate a rough draft of the damaged sequence?

Answer 2

• Translesion polymerases

Question 3

What are mutagens?

Answer 3

• Chemicals that alter specific bases after replication is complete

Question 4

What is photodimerization?

Answer 4

• Exposure to UV light that causes adjacent thymines to covalently link

Question 5

Direct repair

Answer 5

• Corrects mistakes without having to remove any fragments of DNA

Question 6

Base-excision repair

Answer 6

• Use of several enzymes
• Base is removed and the open backbone is known as the AP site
• The AP site is cleaved by AP endonuclease 0-
• Phosphodiesterase excises the deoxyribose phosphate
• The gap is repaired with DNA polymerase I and DNA ligase