AQA A Level Organic Chemistry Addition Polymer Exam Question Help

So I've spent about 45 mins trying to figure out this question (re-learnt naming amines and amides on YouTube lol) and I just don't understand it.

I think I may be drawing the monomer out wrong but I'm not sure. Here's the question:

Polymer M:

---- CH2 -- CH(CH3) -- NH -- CO -- CH2 -- CH(CH3) -- CH2 -- NH--CO -----

Give the IUPAC name of the monomer that forms polymer M.

Mark Scheme Answer:
4-amino-3-methylbutanoic acid

When I draw the mark scheme answer I get:
NH2 -- CH(CH3) -- CH2 -- COOH
And I can't see how this becomes polymer M.

Any help would be appreciated as this is stressing me out lol.

PM is open if need be thanks a lot

I don't think that you have drawn the polymer correctly ...

4-amino-3-methylbutanoic acid only appears once in the polymer structure as a possible monomer are you sure the polymer structure M is correct?

So I've spent about 45 mins trying to figure out this question (re-learnt naming amines and amides on YouTube lol) and I just don't understand it.

I think I may be drawing the monomer out wrong but I'm not sure. Here's the question:

Polymer M:

---- CH2 -- CH(CH3) -- CH2 -- NH -- CO -- CH2 -- CH(CH3) -- CH2 -- NH--CO -----

Give the IUPAC name of the monomer that forms polymer M.

Mark Scheme Answer:
4-amino-3-methylbutanoic acid

When I draw the mark scheme answer I get:
NH2 -- CH2 -- CH(CH3) -- CH2 -- COOH
And I can't see how this becomes polymer M.

Any help would be appreciated as this is stressing me out lol.

PM is open if need be thanks a lot

-CO -- CH2 -- CH(CH3) -- CH2 -- NH-

Is the repeating unit

This can come from

HO-CO -- CH₂ -- CH(CH₃) -- CH₂ -- NH₂

The amine group can condense with the carboxylic acid group with the elimination of water.

Alternatively:

Cl-CO -- CH₂ -- CH(CH₃) -- CH₂ -- NH₂

In this case HCl is eliminated...