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Curly hair in humans (C) is incompletely dominant over straight hair (c). Heterozygous individuals have wavy hair (a new phenotype).  What is the chance a curly-haired female and a straight-haired male have a child with wavy hair?

What is the chance two wavy-haired individuals have a daughter with curly hair?

4 years ago

Answered By Madison L

This means that we would still use the letters C and c, but instead of C being dominant, when combined with c, it creates a new phenotype. The heterozygous state (Cc) is wavy. To have the other states we need homozygous dominant, curly (CC) and straight (cc).

So, a curly haired female will be CC and a straight-haired male will be cc. When crossed, all the children will be Cc, which means 100% of the children will have wavy hair.

Two wavy hair individuals (Cc) will produce CC, Cc, Cc, cc, which means 50% (2/4) will have wavy hair. But they are asking about a daughter specifically, and there is a ½ chance of having a daughter or a son. Therefore, we need wavy hair AND the daughter probability. (2/4) x (1/2)= 2/8. Which when simplified is ¼. So, there is a 25% chance they will have a daughter with wavy hair.