Hi,If a back dog is put to a chocolate bitch will it be a mixed litter of blacks/chocolates or does the black have to carry chocolate to produce chocolates..And can anyone reccomend a good genetics book or websites/...Thanks...

Hi, a black to chocolate can in theory produce a "rainbow" litter i.e all three colours.
If the black is a dominant black i.e not carrying for yellow or choclolate the litter will be all black. An all black or split chocolate/black litter are the most likely results.
Eavie
ps I am assuming you are asking about labradors?