Inheritance and geneics?

In a cross between yellow peaches that are heterozygous for fruit color and skin fuzziness, the genotypic ratio of the offspring is....A- 1:2:4:2:1


B- 1:1:1:1


C- 1:2:1


D- 9:3:3:1


and can you explain why if its not too much because i dont really get it. Thank you

Inheritance and geneics?
This is what is called a dihybrid cross which generally results in a phenotypic ratio (not genotypic) of 9:3:3:1 (assuming no complicating conditions like linked genes or lethal alleles, etc.). Here is why (assuming the genes are on different chromosomes or are unlinked):





If Yellow is Y, then the heterozygote is Yy and if fuzziness if F, then the heterozygous condition if Ff. So, the peach tree genotype for fruit color and fuzziness is: YyFf





So, cross two peach trees:





YyFf x YyFf





There are 16 possible genotypes in the offspring:





YYFF


YYFf


YYFf


YYff





YyFF


YyFf


YyFf


Yyff





YyFF


YyFf


YyFf


Yyff





yyFF


yyFf


yyFf


yyff





This results in phenotypes of:





9 Y-F- (yellow, fuzzy)


3 Y-ff (yellow, non-fuzzy)


3 yyF- (non-yellow, fuzzy)


1 yyff (non-yellow, non-fuzzy)





A Punnett Square with 16 squares will show you this same result. Put the gametes across the top and down the side:


YF, Yf, yF, yf. Good luck, hope this helps!
Reply:have you put the answer's into a punnet square yet ? It will help you understand how they were derybed.