In an alkaline medium,glycine predominantly exists as/in a/an

Given below are two statements $:$
Statement $(I):$ On hydrolysis,oligopeptides give rise to a fewer number of $\alpha$-amino acids,while proteins give rise to a large number of $\beta$-amino acids.
Statement $(II):$ Natural proteins are denatured by acids,which convert the water-soluble form of fibrous proteins to their water-insoluble form.
In the light of the above statements,choose the most appropriate answer from the options given below $:$

Sanger's reagent is used for the identification of which of the following?

What type of bonding helps in stabilising the $\alpha$-helix structure of proteins?

How many of the given compounds will give a positive Biuret test?
Glycine,Glycylalanine,Tripeptide,Biuret.

$A$ protein '$X$' with a molecular weight of $70,000 \ u$,on hydrolysis gives amino acids. One of these amino acids is: