The naturally occurring amino acid that contains only one basic functional group in its chemical structure is

When collagen is boiled with water,it forms

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 $(2)$.

Amino acids containing a heterocyclic ring are:
$(i)$ Histidine
$(ii)$ Valine
$(iii)$ Arginine
$(iv)$ Proline

The correct sequence of amino acids present in the tripeptide given below is

The correct zwitter ion structure of glycine is