You have a male Yellow Labrador Retriever with a brown nose

You have a male Yellow Labrador Retriever with a brown nose that you are going to breed and your extraordinarily-picky partner desperately wants Chocolate Lab puppies. However, the only female mates to which you have access are all Black Labs. Luckily, your friend works for a genetics laboratory and has offered to determine the genotypes of the Black Labs for you.

a) Which Black Lab genotype, if available, would maximize the chances of getting Chocolate Lab puppies?

Would it be BbEE because there\'s an allele for brown (b) and dominant alleles for the deposition into the fur?

b) what other phenotypes might you expect in the litter?

Yellow with brown nose = eebb   

possible black labs = BBEE, BbEE, BBEe, and BbEe

so would it just be the offspring of eebb with all the black labs? So eebb x BBEE, eebb x BbEE, eebb x BBEe, eebb x BbEe

Solution

a) A labrador that has two b\'s and one E will be brown. So the two options are bbEE and bbEe.

BbEE would not give choolate lab puppies,because any lab that contains at least one B and E would be black.

b) other genotypes that may be expected in the litter can be EEBB,EeBB,EEBb,EeBb,eeBB,EEBb,eebb,EEbb,Eebb.