Question

Select the correct option that correctly fill the blanks i - iv
I. Less than (i) of genome represents structural genes that code for proteins.
II. Chemical substance that binds with repressor and convert it into a non-DNA binding State is (ii).
III. In prokaryotes, during replication RNA primer is removed by (iii) whereas in eukaryotes it is removed by (iv).

• A. (i) - 5%, (ii) regulator, (iii) - DNA polymerase II, (iv) - DNA polymerase $\beta$
• B. (i) - 10%, (ii) - regulator, (iii) - DNA polymerase I, (iv) - DNA polymerase $\alpha$
• C. (i) - 2%, (ii) inducer, (iii) - DNA polymerase I, (iv) - DNA polymerase $\beta$
• D. (i) - 50%, (ii) inducer, (iii) - DNA polymerase III, (iv) - DNA polymerase $\alpha$

Answer 1

Answer: (C)

(i) - 2%, (ii) inducer, (iii) - DNA polymerase I, (iv) - DNA polymerase $\beta$

The human genome is made of 3 billion DNA base pairs and out of them 2% only are responsible for coding for proteins and the rest may have regulatory functions. In an inducible operon such as the Lac Operon the inducer binds to the repressor to inactivate it such that the repressor can no longer bind to the operator and the gene expression can take place. DNA polymerase I (or Pol I) is an enzyme that participates in the process of prokaryotic DNA replication. This is responsible for proof reading and excising or removing off the RNA primers required for initiation of replication. DNA polymerase, beta, also known as POLB, is an enzyme present in eukaryotes involved in base excision and repair, also called gap-filling DNA synthesis.

So, the correct option is '(i) - 2%, (ii) inducer, (iii) - DNA polymerase I, (iv) - DNA polymerase β '.