Question

What is the genotype ration between the cross YyRr x YyRr

Answer 1

I believe it's 1:2:1
When you a dihybrid punnet square the results are YYRR:1/ YyRr: 2 /yyrr:1

Answer 2

Answer: 1YYRR, 2YYRr, 1YYrr, 2YyRR, 4YyRr, 2yyRR, 1yyRR, 2yyRr, 1yyrr

Explanation: YyRr x YyRr is a dyhibrid cross in which we must apply independent assortment that states that alleles of different genes assorted independently and do not affect the assortment of each other. This means that for and individual with a genotype YyRr is posible to produce 4 gametes:

YR, yR, Yr, yr

Since both parents have the same genotype, punnet square for this cross is

`\left[\begin{array}{ccccc}&Yr&YR&yr&yR\\Yr&YYrr&YYRr&Yyrr&YyRr\\YR&YYRr&YYRR&YyRr&YyRR\\yr&Yyrr&YyRr&yyrr&yyRr\\yR&YyRr&YyRR&yyRr&yyRR\end{array}\right]`

Looking at the genotypes obtained the ratio is 1YYRR, 2YYRr, 1YYrr, 2YyRR, 4YyRr, 2yyRR, 1yyRR, 2yyRr, 1yyrr