Hello,


Zwitter ion is a functional group which has atleast one positive and one negative charge.
Amino acids are the best-known examples of zwitterions. They contain an amine group (basic) and a carboxylic group (acidic). The -NH2 group is the stronger base, and so it picks up H+ from the -COOH group to leave a zwitterion
And glycine
(NH2-CH2-COOH),  is the simplest amino acid. It contains both a carboxyl as well as an amino group, so can form a zwitterion.


But in case of aniline(C6H5NH2) there is no carboxyl group.

Thus, gylcine can form zwitter ion where aniline cannot.

I hope this helps.

Hello dear..
Aniline does not form zwitter ion because it have only baisc group amine.It does not have carboxylic group.Glycine can exist in zwitter ionic form.You can take more information about this from NCERT chemistry part 2 of class 12 biomolecule chapter.
Hope you get it.