One species of tree has a very large genome consisting of 2.0 × 10¹⁰ base pairs of DNA.
(a) If this DNA was organized into a single linear molecule, how long (meters) would this molecule be? 

(b) If the DNA is evenly distributed among 10 chromosomes and each chromosome has one origin of DNA replication, how long would it take to complete the S phase of the cell cycle, assuming that DNA polymerase can synthesize 2 × 10⁴ bp of DNA per minute? 

(c) An actively growing cell can complete the S phase of the cell cycle in approximately 300 minutes. Assuming that the origins of replication are evenly distributed, how many origins of replication are present on each chromosome?

(d) What is the average number of base pairs between adjacent origins of replication?