I need help studying for a biology quiz?

[Anne]

There's going to be questions on the test on dihybrid crosses and on the study there is a sample question. I have no clue! The question says this:

Perform a dihybrid cross mixing colour and texture with R's representing color, and Su's representing texture. The cross is at the F2 generation

R = Purple
r = Yellow
Su = Starchy/Smooth
su = Sweet/wrinkled
I also need to know how to do phenotype probability ratios for the problem.

 

[random]

Ok, you know how a monohybrid cross is the basic punnet square right? well a dihybrid cross is just a 4x4 cross instead of a 2x2 cross.
So just do it like you do it with a basic punnet square.

R | r | Su | su |
-
R
-
r
-
Su
-
su

and then add them. It's really that simple...