The E. coli chromosome is 1.28 mm long. Under optimal conditions, the chromosome is replicated in 40 minutes.

Part A
What is the distance traversed by one replication fork in 1 minute?
Express your answers using two significant figures.

Part B
If replicating DNA is in the B form (10.4 base pairs per turn), how many nucleotides are incorporated in 1 minute in one replication fork?
Express your answers using three significant figures.

Part C
If cultured human cells (such as HeLa cells) replicate 1.2 m of DNA during a five-hour S phase and at a rate of fork movement one-tenth of that seen in E.coli, how many origins of replication must the cells contain?
Express your answers using four significant figures.

Part D
What is the average distance, in kilobase pairs, between these origins?
Express your answers using four significant figures.