Which of the following basic amino acids is the least basic?

In $\text{alanyl-glycyl-leucyl-alanyl-valine}$,the number of peptide linkages is $......$

Identify the acidic amino acid from the following list represented by three-letter symbols.

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $A$ solution of the product obtained by heating a mole of glycine with a mole of chlorine in the presence of red phosphorus generates a chiral carbon atom.
Reason $R$: $A$ molecule with $2$ chiral carbons is always optically active.
In the light of the above statements,choose the correct answer from the options given below:

$A$ sequence of how many nucleotides in messenger $RNA$ makes a codon for an amino acid?

Which of the following can be used to detect the presence of $\alpha$-amino acids?