Question

Explain one system of cascade regulation in genetics

Answer 1

DNA Replication in Prokaryotes.

1. Origin of the replication is identified. Then unwinding of parental DNA with the help of DNA helicase to form a replication fork. Topoisomerase and DNA gyrase also helps in the unwinding process.

2. RNA primer complementary to the DNA template is synthesized by RNA primase.

3. DNA synthesis is continous in the leading strand ( towards replication fork) by DNA polymerase.

4. DNA synthesis is discontinous in the lagging strand ( away from the fork ) as Okazaki fragments.

5. Elongation : In both strands , the synthesis is from 5' to 3' direction.

6. Then the RNA pieces are removed , the gaps are filled by deoxy nucleotides by DNAP and the pieces are ligated by DNA ligase .

7. Proof reading is done by the DNA polymerase.

8. Finally organised into chromatin.

9. Main enzymes involved are : DNA polymerase, helicase, topoisomerase, DNA primase, Single strand binding proteins, and DNA ligase.