Question

Because all DNA polymerases synthesize DNA in the 5′-to-3′ direction, and the parental strands are antiparallel, DNA replication is accomplished with the use of two mechanisms: continuous and discontinuous replication. Indicate whether the following items relate to (1) continuous replication, (2) discontinuous replication, or (3) both modes of replication.

1) (1) continuous replication
2) (2) discontinuous replication
3) (3) both modes of replication

Answer 1

Continuous replication refers to the synthesis of the leading strand towards the replication fork, while discontinuous replication involves the creation of Okazaki fragments on the lagging strand. Both types share common features such as the use of enzymes and the 5' to 3' directionality of nucleotide addition.

Step-by-step explanation:

During DNA replication, because of the antiparallel nature of the double helix, one strand, known as the leading strand, is synthesized continuously towards the replication fork. This process falls under continuous replication (1). Conversely, the lagging strand is synthesized in short, discontinuous sections called Okazaki fragments, which are later joined together.

This process is known as discontinuous replication (2). Both modes of replication involve the participation of various enzymes, the opening of the DNA double helix by helicase, and the addition of nucleotides in the 5' to 3' direction, illustrating aspects common to (3) both modes of replication.