$A$ bioreactor is

Recombinant $\text{DNA}$ is directly injected into the nucleus of an animal cell by $-$

What is required for the expression of a foreign gene?

Southern blotting is done for

Given below are two statements.
Statement $I$ - The isolated $DNA$ of donor organism is cleaved by suitable restriction endonuclease to form $DNA$ fragments with cohesive staggered or blunt ends.
Statement $II$ - The foreign $DNA$ or passenger $DNA$ can also be obtained directly from genomic or cDNA library.
In the light of above statements,select the correct option given below:

Explain $PCR$ in short.