Question

When two loci are unlinked, the offspring observed in a dihybrid cross in the F2 are:

a.) all the recombinant types

b.) all the parental types

c.) 50% of recombinant, and 50% parental types

d.) 25% of recombinant types, and 75% parental types

e. None of the above

Answer 1

e. none of the above

Dihybrid cross is a cross between two different lines/genes that differ in two observed traits. According to Mendel's statement, between the alleles of both these loci there is a relationship of completely dominant - recessive traits.

F1 generation all show the dominant traits of two characters

F2 generation show for combination of traits in a9:3:3:1 ratio in which 9 shows the dominant parental character and 1 shws the recessive parental character.

3+3shows the recombinant characters

ie,10 patental types : 6 recombinant types

parental generation (P) AABB abb F, generation self-pollinated AaBb pollen ABAbaBab AABB AABb AaBB Aalb AABb Abb AaBb Aabb ovules F2 generation ABB AaBb aaBb aaBb O AaBb Aabb aaBb aabb

please do refer the image