2 Tt : 2 tt

Right, or it could also be reduced to a 1 Tt : 1 tt ratio



Ready to go on?


Problem #3

So far we have been working with only one trait or a monohybrid cross. There have been two possibilities (tall or short), but it is only one trait (height). Now we are going to work with 2 traits - height and color of the peas. The trick to dihybrid crosses (two traits) is that you have to keep a height gamete (tall or short) with a color gamete (yellow or green) at all times.


We are going to cross a homozygous tall yellow plant with a short green plant.


___________ x _______________


What is the genotype of the homozygous tall yellow plant? ________


Well, let's break it down a little further.


What is the genotype of the homozygous tall part?

a. TT

b. Tt

c. tt

d. YY