Capacité de l'organisme à se défendre contre un microbe et à résister à la maladie causée
par cet agent infectieux?

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)

helicase, i think thats it

answer; /// the shaft of the hair consists of dead cells;