Week 5: Chromosomes, genomes and DNA replication

Question 1

Describe the genetic material of bacteria.

Answer 1

• Single, circular, double-stranded DNA molecule
• No histone proteins
• Contain plasmids

Question 2

What is semi-conservative replication?

Answer 2

• DNA double helix is unwound, each strand specifies a new daughter strand by base pairing
• New strands are wrapped around the old ones
• Meselson and Stahl, 1958

Question 3

Describe the DNA replication fork.

Answer 3

• Leading strand= continuous replication
• Lagging strand= discontinuous replication creating okazaki fragments