AP BIOLOGY

Detailed explanation-1: -The separation of the two single strands of DNA creates a ‘Y’ shape called a replication ‘fork’. The two separated strands will act as templates for making the new strands of DNA. One of the strands is oriented in the 3’ to 5’ direction (towards the replication fork), this is the leading strand?.

Detailed explanation-2: -DNA replication initiates at specific points, called origins, where the DNA double helix is unwound. A short segment of RNA, called a primer, is then synthesized and acts as a starting point for new DNA synthesis. An enzyme called DNA polymerase next begins replicating the DNA by matching bases to the original strand.

Detailed explanation-3: -The sites where separation and replication occur are called replication forks.

Detailed explanation-4: -The RF is a multiprotein complex with helicase and DNA synthesis activities. It is called a fork because the structure resembles a two-pronged fork. The helicase activities unwind DNA in front of the fork to create regions of singled-stranded DNA (ssDNA).

Detailed explanation-5: -DNA helicase is needed in order to open the DNA to expose the nucleotide bases that are used as the template for replicating the DNA. The area of the DNA that is opened by DNA helicase is known as the replication fork because it looks very similar to a fork in the road.