After a mutation at a genetic locus,the character of an organism changes due to the change in:

Read the following statements carefully and choose the correct statements.
$(A)$ In a transcription unit,the promoter is located at the $5'$ end of the coding strand.
$(B)$ The single strand $DNA$ having the polarity $5' \rightarrow 3'$ is the template strand.
$(C)$ $RNA$ polymerase binds to the operator during transcription.
$(D)$ Single base $DNA$ differences occurring in humans are called Single Nucleotide Polymorphisms $(SNPs)$.

Define the following terms: Replication fork and Transcription.

Match the researchers in Column-$I$ with their work given in Column-$II$.

Column-$I$	Column-$II$
$i$. Avery,McCarty,and MacLeod	$a$. $DNA$ digested by DNAse inhibits transformation of $R$ cells to $S$ cells.
$ii$. Griffith	$b$. $DNA$ replication is semi-conservative.
$iii$. Hershey and Chase	$c$. Used Streptococcus pneumoniae.
$iv$. Meselson and Stahl	$d$. Used radioactive Sulphur and Phosphorus.

Select the correct option from the following.

Read the following statements and select the correct statements:
$(A)$ Essential life processes such as metabolism,translation and splicing are evolved around $\text{RNA.}$
$(B)$ Heavy isotope of nitrogen $(^{15}N)$ is a radioactive isotope,while light isotope of nitrogen $(^{14}N)$ is not a radioactive isotope.
$(C)$ The codon in $\text{rRNA}$ is read in a contiguous fashion.
$(D)$ In the first phase of translation,amino acids are activated in the presence of $\text{ATP.}$
$(E)$ $\text{DNA}$ from every tissue from an individual shows a high degree of polymorphism.
Choose the correct answer from the options given below:

For protein synthesis,$P$ can directly code,while each nucleotide of $Q$ has a $2'-OH$ group in its sugar. Identify $P$ and $Q$.
$\quad\quad P\quad Q$