How many different genotypes are produced in the cross Aa Bb Cc × Aa Bb Cc?

Question

1. 8

2. 9

3. 12

4. 27

5. 30

Answer 1

A trihybrid cross gives an 8 x 8 Punnett Square resulting in 64 "boxes" with 8 different phenotypes in the ratio 27:9:9:9:3:3:3:1. The grand total of all the different genotypes which are possible is 27.

A simple rule:

1.Monohybrid Phenotypic ratio is 3:1 & are 3 genotypes.

2.Dihybrid Phenotypic ratio is 9:3:3:1 & are 9 genotypes.

3. Trihybrid Phenotypic ratio is 27:9:9:9:3:3:3:1 & are 27genotypes.

That is the way the numbers work out.

If you have any doubts see this link where all the Punnett Squares are given as examples -http://www.bcc.orst.edu/bio/classes/bi10...

Answer 2

Since each trait is heterozygus, it is possible to obtain three different genotypes (AA, Aa, aa) from each allele. Using basici probabilities:

3 x 3 x 3 = 27

(4) Therefore, 27 different genotypes are possible from the cross.

Answer 3

These answers are wrong. Its 64 possibilities.

The Ratio of a Trihybrid Cross is:

27:9:9:9:3:3:3:1

Maybe you meant how many phenotypes can be produced....thats 8.