Which is true of an Okazaki fragment?

Question. Which is true of an Okazaki fragment?

Select one:

found on leading strand, replication in 3’ to 5’ direction

found on lagging strand, replication in 5’ to 3’ direction

found on lagging strand, replication in 3’ to 5’ direction

shortens the telomere in a chromsome

found on leading strand, replication in 5’ to 3’ direction

Answer:- The correct option is 3. found on lagging strand, replication in 3’ to 5’ direction

Okazaki fragments are short, nascently synthesised DNA segments that arise on the lagging strand during DNA replication.

A DNA polymerase can only add new nucleotides to the 3’end of an emerging strand. On the leading strand, synthesis can occur continuously in 5’ to 3’ direction.

On the laggard strand; however, synthesis occurs in a direction opposite to that of movement of the replication fork. Short stretches of Okazaki fragments are, thus synthesized in the 3’ to 5’ direction on the lagging strand.

The other options are incorrect:

1. Okazaki fragments are not present in the leading strand.

2. 3’ to 5’, not the other way around.

3. They do not participate in the process of shortening telomere.

4. The leading strand synthesizes from 5’ to the 3’.

Therefore, the statement that applies to Okazaki fragments is the lagging strand replication process occurs in a 3′-5’ direction.