AP BIOLOGY

Detailed explanation-1: -The strand that runs in the 5’ to 3’ direction in the replication fork is referred to as the leading strand. The strand is replicated discontinuously.

Detailed explanation-2: -Leading Strand and Lagging Strand The first one is called the leading strand. This is the parent strand of DNA which runs in the 3’ to 5’ direction toward the fork, and it’s replicated continuously by DNA polymerase because DNA polymerase builds a strand that runs antiparallel to it in the 5’ to 3’ direction.

Detailed explanation-3: -DNA is always synthesized in the 5’-to-3’ direction, meaning that nucleotides are added only to the 3’ end of the growing strand.

Detailed explanation-4: -Which way’s which? When we look at a sequence of DNA, we read it in the 5′-3′ direction. The relative positions of genes or other sites along a DNA strand can be described as upstream (towards the 5′ end) or downstream (towards the 3′ end).

Detailed explanation-5: -DNA replication goes in the 5’ to 3’ direction because DNA polymerase acts on the 3’-OH of the existing strand for adding free nucleotides.