AP BIOLOGY

Detailed explanation-1: -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. The other strand is called the lagging strand .

Detailed explanation-2: -The leading strand is the strand of nascent DNA which is synthesized in the same direction as the growing replication fork. The synthesis of leading strand is continuous. The lagging strand, on the other hand, is the strand of new DNA whose direction is opposite to the direction of the growing replication fork.

Detailed explanation-3: -The leading strand is synthesized by adding nucleotides to the 3’ end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5’ end. The lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together.

Detailed explanation-4: -Lagging strand: Chunks of DNA, called Okazaki fragments, are then added to the lagging strand also in the 5’ to 3’ direction. This type of replication is called discontinuous as the Okazaki fragments will need to be joined up later.

Detailed explanation-5: -First, a so-called initiator protein unwinds a short stretch of the DNA double helix. Then, a protein known as helicase attaches to and breaks apart the hydrogen bonds between the bases on the DNA strands, thereby pulling apart the two strands.