"mięso" is neuter (like "dziecko") and "twój" should be inflected into "twoje" (twoje dziecko, mięso, krzesło, zwierzę - all of them are neuter)

Twoje is neuter and must agree with the neuter noun. Generally, nouns that end in -o are neuter.

twój/twoja/twoje/twoi etc- belonging to you=1 person
wasz/wasza/wasze/wasi etc - belonging to you = 2+people

mój, twój, nasz, wasz- my, your, our, your(plural)- describing a singular masculine noun in nominative case, or singular masculine not animated noun in accusative case.

moje, twoje nasze, wasze - describing singular neuter noun in nominative or accusative case; describing a plural not masculine personal noun in nominative or accusative case

Duolingo algorithm sometimes puts one sentence from a totally different skill into your lesson. Nothing we can do about it, there's no point in complaining. Theoretically it's a random check of whether you still remember it.

However it's not. It's only the difference between singular and plural. Using "wasze" when talking to a single person will seem very weird (although there's quite a chance that your interlocutor will understand that you confused Polish and Russian).

In formal speech we refer to a man as "pan", to a woman as "pani", and then there's "panowie" (gentlemen), "panie" (ladies) and "państwo" (mixed gender plural). It's used with forms of 3rd person - singular or plural, respectively. You will encounter it later during the course.

The form of possessive depends on the gender of the noun it describes (and the case). But staying in Nominative, like this simple phrase here, you have:

twój (masculine): twój dom

twoja (feminine): twoja książka

twoje (neuter): twoje mięso

twoi (masculine personal plural): twoi rodzice

twoje (not masculine-personal plural): twoje psy

Not sure if you had plurals already or not.

Added.