Polymerase chain reaction $\text{(PCR)}$ amplifies $\text{DNA}$ following the equation:

Elution means

Can a disease be detected before its symptoms appear? Explain the principle involved.

Diagrammatically represent the experimental steps in cloning and expressing a human gene (e.g.,the gene for growth hormone) in a bacterium like $E. coli$.

The steps involved in the Southern blot test are as follows:
$I.$ $X-ray$ film
$II.$ Electrophoresis
$III.$ Digestion with restriction enzyme
$IV.$ Ethidium bromide
$V.$ Radioactive probe
Choose the option having the correct sequential order of these events.

In which type of bioreactor do air bubbles increase the oxygen transfer area?