Question

How many phenotypic classes are expected in the progeny of a FOUR-POINT test cross?

a) 2
b) 8
c) 16
d) 32

Answer 1

There are 16 different phenotypic classes expected in the progeny of a four-point test cross.

Step-by-step explanation:

In a four-point test cross, there are 8 different genotypes that can be produced. Each genotype represents a different combination of alleles from two separate gene loci. Since each gene locus can have 2 alleles, the number of genotypes is calculated as 2^2 = 4 for each locus, and 4 x 4 = 16 for both loci. Therefore, there are 16 different phenotypic classes expected in the progeny of a four-point test cross. Option c) is the correct answer.