The black fur is dominant over white(light) colour which means black fur trait only require one copy of allele to express itself.
Key
B=black
b=white
- Provided that the genetic cross is between genotype (BB) and (bb).
so, the probability that the offspring of this cross will have black fur is 100%.
2. Provided that the genetic cross is between genotype (Bb) and (bb).
so, the probability that the offspring of this cross will have black fur is 50%.