Question

A trihybrid cross is a cross between two individuals who are heterozygous for three genes. For example: AaBbCc x AaBbCc. Assuming these three genes are unlinked and assorting independently, what segregation ratio would be observed?

Answer 1

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

Step-by-step explanation:

The gametes of the parental genotypes would be

ABC, ABc, AbC, aBC, Abc, aBc, abC, abc

The cross between AaBbCc and AaBbCc will result into following offspring (image is also attached)

ABC ABc AbC aBC Abc aBc abC abc

ABC AABBCC AABBCc AABbCC AaBBCC AABbCc AaBBCc AaBbCC AaBbCc

ABc AABBCc AABBcc AABbCc AaBBCc AaBbcc AaBBcc AaBbCc AaBbcc

AbC AABbCC AABbCc AAbbCC AaBbCC AAbbCc AaBbCc AabbCC AabbCc

aBC AaBBCC AaBBCc AaBbCC aaBBCC AaBbCc aaBBCc aaBbCC aaBbCc

Abc AABbCc AABbcc AAbbCc AaBbCc AAbbcc AaBbcc AabbCc Aabbcc

aBc AaBBCc AaBBcc AaBbCc aaBBCc AaBbcc aaBBcc aaBbCc aaBbcc

abC AaBbCC AaBbCc AabbCC aaBbCC AabbCc aaBbCc aabbCC aabbCc

abc AaBbCc AaBbcc AabbCc aaBbCc Aabbcc aaBbcc aabbCc aabbcc

The genotype ratio is 27:9:9:9:3:3:3:1