CATDOLL : Why does a white cat give birth to a black cat?

The reason why a white cat can give birth to a black cat is mainly due to genetics. The white cat's coat color does not mean that it does not have the black gene, but that these genes are not expressed. In cat genetics, the inheritance of coat color is complex and involves the role of multiple genes. White cats may carry black genes, but these genes are not expressed in white cats because the white gene covers the expression of other colors.

However, when a white cat mates with another cat, there is a chance that their offspring will inherit the black gene and express it, resulting in a black cat.