Question

How many genotypes are possible for the offspring?explain

Answer 1

Vague, but I am going to assume you're talking about a phenotypic trait the is a dominant trait controlled by on pair of genes.
Ex: the ability to roll your tongue is controlled by a pair of genes and no more. The gene that gives.the tongue rolling ability (we"''ll call R, is dominant to the gene for not being about to roll your tongue. We'll call this gene r.
If you inherit the phenotype for tongue rolling, you have two possible phenotypes: RR or Rr. Both genotypes make you a tongue roller. If you can NOT roll your tongue, your genotype can only be rr.

Answer 2

How many genotypes are possible for the offspring?

Usually when you are trying to figure out different possibilities of offspring using punnet squares, 4 genotypes can be figured out. I think that it also depends on how you are finding out the different genotypes for offspring.

Hope This Helped! :3