Question

How many true breeding genotypes could be produced by a dihybrid selfing?

Please show how and why

Answer 1

Answer:

True breeding genotypes at both genotypes are AABB, AAbb, aaBB & aabb

Explanation:

AaBb X AaBb

The genotype AaBb (Dihybrid) produces 4 types of gametes in equal proportion. According to the law of independent assortment, an allele of a gene independently assort with any allele of the second gene during formation of gametes from Dihybrid.

The four gametes are AB, Ab, aB & ab.

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

Total 9 type of geneotypes would be produced as below:

1). AABB

2). AABb

3). AAbb

4). aaBB

5). aaBb

6). Aabb

7). AaBB

8). AaBb

9). Aabb

True breeding genotypes at both genotypes are AABB, AAbb, aaBB & aabb