B: Black body
b: brown body
Bb+Bb= BB, Bb, Bb, bb
Not my drawing and labeling but this is a clear picture of it.
Source:
http://leavingbio.net/amoeba/
5 ........................
I believe it's called a sex-linked trait, if I'm remembering correctly. This is because men do not have an X chromosome, therefore it would be linked to females.