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 and b) what other phenotypes might you expect in the litter? SHOW YOUR WORK!

Solution

The genetic combinations involve:

BB= both parents provide a black gene

Bb= mother supplies black and father supplies brown or vice-versa

bb= both parents provide a brown gene

Also,

EE= Both parents provide the gene permitting pigment deposition

Ee= Mother supplies gene for permitting gene deposition and father supplies genes preventing pigment deposition or vice-versa.

ee= both parents provide genes preventing pigment deposition

a. Genotypes EEbb and Eebb produce chocolate color puppies.

b. When we cross EEbb and Eebb, the offsprings produced have folllowing genotypes: EEbb and Eebb.