In rabbits, the dominant allele C is required for coloured fur; the recessive allele c makes the fur colourless (albino). In the presence of at least one C allele, another gene determines whether the fur is black (B, dominant) or brown (b, recessive). A homozygous strain of albinos. The F1 were then crossed to homozygous double recessive rabbits, yielding the following results: black 35; brown 66; albino 100. Are the genes b and c linked? What is the frequency of recombination? Diagram the crosses, showing the arrangement of the genetic markers on the chromosomes.