Which of the following amino acids possesses two chiral centres?

Treatment of compound $O$ ($1,2-$diethylbenzene) with $KMnO_4 / H^{+}$ gives $P$ (phthalic acid),which on heating with ammonia gives $Q$ (phthalamide). The compound $Q$ on treatment with $Br_2 / NaOH$ produces $R$ ($o-$phenylenediamine). On strong heating,$Q$ gives $S$ (phthalimide),which on further treatment with ethyl $2-$bromopropanoate in the presence of $KOH$ followed by acidification,gives a compound $T$.
$(1)$ The compound $R$ is
$(2)$ The compound $T$ is
$(A)$ glycine
$(B)$ alanine
$(C)$ valine
$(D)$ serine
Identify the correct options for $(1)$ and $(2)$.

In the given pentapeptide, find out an essential amino acid $(Y)$ and the sequence present in the pentapeptide: Choose the correct answer from the options given below:

Zwitter ion is formed by

Proteins are condensation polymers of......

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

List-$I$ Natural Amino acid	List-$II$ One Letter Code
$A$. Arginine	$I$. $D$
$B$. Aspartic acid	$II$. $N$
$C$. Asparagine	$III$. $A$
$D$. Alanine	$IV$. $R$

Choose the correct answer from the options given below :-