Solve

Solve 39. O. s (d) dihybrid cross (Main 2010) In Antirrhinum two plants with pink flowers were hybridized. The F] plants produced red, pink and white flowers in the proportion of I red, 2 pink and I white. What could be the genotype of the two plants used for hybridization? Red flower colour is determined by R R, and white by rr genes. (a) rrrr (d) rr (Main 2010) Select the incorrect statement from the following. (a) galactosemia is an inborn error ofmetabolism

Ok we know that when RR x rr , in the F₁ it produces all pink and in the F₂ red, pink and white in the ratio 1:2:1.
We just need to remember that in F₁ - we cross the parents(similar or diff genotypes) and in the F₂ we cross the F₁ progeny with itself. Always.

So since in this case we are getting the F₂ ratio in F₁ itself.
So the two parent have to be Rr and Rr.

Here in this ques we can also eliminate. The ques mention 'the parents' indicating both the parents are of the same genotype. So we can cross out RR - since RR x RR - will give all red plant.
rr x rr - will give all white plants

and rrrr doesn't even fit the norm as it shows a dihybrid prototype but with a single character (colour) into consideration ---- leaving behind Rr.

Hope this helepd ! :))