Question

The lagging daughter strand of DNA is synthesized in what appears to be the “wrong” direction. This synthesis is accomplished by:
A. Ligating (connecting) short Okazaki fragments that are synthesized in short spurts in the “right” direction.
B. Primase
C. Using multiple primers and DNA polymerase I
D. Both A and B

Answer 1

Hint: The Okazaki fragments on the lagging strand are linked together to form a continuous new DNA molecule. The Okazaki fragments were discovered by labeling Escherichia coli with 3 H-thymidine in situations that decreased cell growth and division.

Complete step by step solution:
The complementary strands in the double DNA are synthesized at varying rates throughout replication. Replication initially starts with the leading strand. Replication begins afterward, moves quite slowly, and therefore is interrupted on the lagging strand.
The lagging strand can be referred to as the DNA strand which is replicated in the 3' to 5' way from the template strand throughout DNA replication. It is synthesized in pieces.
The synthesis of the chain on the lagging strand is discontinuous in the 5' to 3' direction due to the operational confinements of the DNA polymerase being not able to synthesize the chain in the 3' to 5' direction. The non - continuous replication produces so many short segments known as Okazaki fragments.
Since the lagging strand is looped throughout replication, it causes the "trombone model" to be constructed.

Hence, the correct option is D.

Note:
A single primer is required for leading strand synthesis, whereas numerous RNA primers are needed for lagging strand synthesis. Having followed primer synthesis, the leading strand appears to require only DNA polymerase to proceed with replication, while the lagging strand requires multiple enzymes, which include DNA polymerase I, RNase H, and ligase.