What are the 6 most common elements in living things?

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 three components of a nucleotide are the nitrogenous base, the phosphate group and the five-carbon sugar.