Answer:
they might get their long hair from their father's genes. They might also have long hair phenomenally.
Although the mother may look shorthaired, she may be carrying a hidden, or recessive, longhaired mutation. So if she mates with a longhaired tom, half the kittens will be longhaired. Or if she mates with a shorthaired tom carrying the same hidden longhaired gene, one in four kittens will be longhaired.
