Answer :
punnet square 1:
homozygous (LL: normal) or (ll: affected) homo meaning same
recessive (ll)
Square would look like:
Ll, Ll, Ll, Ll= 100% of the cats will be carrier of short hair genes.
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punnet square 2: if the male was affected he would also have ll as his traits, which would make 100% of their offspring affected mutants....meaning they would all have recessive traits.
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Since you did not say that the male was affected and that he was a true breeding short haired male, then punnet square 1 is what you need to look at. I put square 2 up so that you could see what the ratio would be if both male and female cats had (ll) alleles.
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Hopefully this helped and good luck.