TRIHYBRID CROSS!!!

[lreitz4]

I have a question about how to set up a trihybrid cross. the information is:


A woman who is heterozygous for right handedness, has blue eyes, and heterozygous for freckles marries a man who is heterozygous for right handedness, green eyes, and freckles. They come to you as a genetic counselor to help them calculate the odds on having a child with all the combination of appearances.

R-right handed B-green eyes F-freckles
r-left handed b-blue eyes f-no freckles


any help would be greatly appreciated.

[mith]

well start by writing out the genotypes

[lreitz4]

RrbbFf RrBbFf

how do i cross them

[mith]

first, you should do the crosses as you would for single i.e. do each trait separately.

then the probabilities of the combination is the probabilities of each individual trait multiplied together.