Separated virus and bacteria in centrifuge. So virus inject DNA into the bacterial cell. Two parallel strands of alternating sugar groups and phosphate groups. Information equivalent to 4000 books of 500 pages each. First DNA is uncoiled by helicases.
Humans get nucleotide building blocks by digesting the DNA in the food they eat.
There is more than one initiation site. The resulting DNA segments are united using ligase. Replication is in 5 to 3 direction DNA polymerase adds nucleotides only at the 3 hydroxyl end of the new DNA strand. ID hair, blood, sperm at crime scene. Mitochondrial DNA to reveal evolutionary relationships of modern human populations.