Please Help me with this question Assuming independent assor

Please Help me with this question!

Assuming independent assortment, imagine a dihybrid plant with genotype AaBb. If A is dominant to a, and B is dominant to b, what phenotypic ratio is produced from: (1) selfing, (2) from a testcross? 3:1, 1: 1 1:1; 3:1 9:3:3:1, 3:1 1:2:1; 1:1 9:3:3:1, 1:1:1:1

Solution

In the case of SELFING:

AaBb X AaBb will yield the following outcomes:

In this way you get:

So, phenotypic ratio produced from selfing is 9:3:3:1.

In the case of TESTCROSS:

AaBb X aabb will yield the following outcomes:

In this way you get one phenotype of each type. That is:

So, phenotypic ratio produced from testcross is 1:1:1:1.

	AB	Ab	aB	ab
AB	AABB	AABb	AaBB	AaBb
Ab	AABb	AAbb	AaBb	Aabb
aB	AaBB	AaBb	aaBB	aaBb
ab	AaBb	Aabb	aaBb	aabb