Final Exam Chapter 5 & 6

Question 1

Introns and exons

Answer 1

• Coding sequence: Exon

- Non-coding sequence: Introns (10 times more than exons)

Question 2

Repetitive DNA sequences

Answer 2

50% of mammalian DNA has repetitive sequences

Question 3

DNA Polymerases

Answer 3

• Replicate & Repair

- 5’ to 3’ direction

Question 4

Replication fork

Answer 4

• Strands separate and serve as templates at the replication fork
• Leading and lagging strands

Question 5

Fidelity of replication

Answer 5

DNA Polymerases selects the correct base and proof reads

Question 6

Origins and initiation of replication

Answer 6

Binding sites for proteins to initiate replication

Question 7

Telomeres and Telomerase

Answer 7

• Telomeres are the caps at the end of each strand of DNA that protect our chromosomes
• Accomplished by Telomerase

Question 8

Direct reversal of DNA damage

Answer 8

• DNA lesions are Pyridine Dimers & Alkylated Guanine

- repaired by direct reversal

Question 9

Excision repair

Answer 9

-Most DNA damage is repaired by excision
Gap is filled by new DNA
-Base excision vs nucleotide excision

Question 10

Double strand breaks

Answer 10

recombination repair