Question

Consider three genes, Aa, Bb and Cc, each of which affects a different character. The three genes are located on different chromosomes. Calculate the probability of obtaining: a) An Aa BB Cc zygote from a cross of Aa Bb Cc x Aa Bb Cc b) An Aa BB cc zygote from a cross of aa BB Cc x AA bb CC

Answer 1

Total no of zygotes is 64.

(a)$P(Aa BB Cc)=\frac{4}{64}=\frac{1}{16}$

cross between alleles -

(I)ABC-aBc

(II)ABc-aBC

(III)aBC-ABc

(IV)aBc-ABC

(b)$P(Aa BB cc)=0$

No zygote is formed of the following orientation by the cross.

Cross between alleles are-

(I)aBC-AbC

(II)aBc-AbC