A woman with straight hair marries a man with curly hair and, who is known to be heterozygous for the trait. What is the chance that their first child will have curly hair?

Curly hair is the dominant trait and straight hair is the recessive trait. As the father is heterozygous for the trait curly, he Cc as genotype and mother has the genotype as cc. The child could inherit genotypes Cc (curly) or cc (straight). Hence, the child has one in two chance of inheriting curly hair.