Describe the skeleton of sponges

Sponges have an internal skeleton that gives them support and protection. ... A sponge endoskeleton consists of short, sharp rods called spicules, Spicules are made of silica, calcium carbonate, or spongin, a tough protein. They grow from specialized cells in the body of the sponge.

Explanation:

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)

the answer to your question is sperm