One functional unit of a gene which specifies the synthesis of one polypeptide is known as:

In which process does the transfer of genetic information occur from $RNA$ to $DNA$?

The diagram shows an important concept in the genetic implication of $DNA$. Fill in the blanks $A$ to $C$.

The $T_4$ bacteriophage $rII$ mutant strain fails to lyse $E. coli$. However,when two strains $rII^X$ and $rII^Y$ are mixed,they lyse $E. coli$. What is the possible reason for this?

Match List-$I$ with List-$II$:

List-$I$	List-$II$
$A$. Monocistronic gene	$I$. Coding sequence
$B$. Polycistronic gene	$II$. Intervening sequence
$C$. Exons	$III$. Mostly prokaryotes
$D$. Introns	$IV$. Mostly eukaryotes

How many of the following statements are correct?
$I - RNA$ is formed from $DNA$ by the process of transcription.
$II - DNA$ is more stable than $RNA$.
$III - RNA$ acts as a catalyst (enzyme) in some biochemical reactions.
$IV - DNA$ is resistant to mutations due to its double-helical structure and the presence of complementary strands that allow for repair mechanisms.