A couple with curly haired husband and straight haired wife have all their children curly haired because
A couple with curly haired husband and straight haired wife have all their children curly haired because
The correct option is D Both the parents are homozygous
The couple have contrasting traits for hair type, curly and straight. From the description, we find that all the children are curly haired, indicating that curly hair is dominant over straight hair. Let us assume that the hair type gene is represented as 'C'. The father could have either of the two genotypes CC or Cc. The mother, being straight haired, would be homozygous recessive, cc. Assuming that all the children born to the couple are curly haired, the genotype of the father should be CC, that is, homozygous dominant. Children born to the homozygous dominant father (CC) and homozygous recessive mother (cc), will be heterozygous dominant (Cc) and will have curly hair. If the second scenario was true, where the father is heterozygous dominant (Cc), it is possible that at least one child born to the couple will have the recessive phenoype of straight hair.
Both the parents are homozygous
The couple have contrasting traits for hair type, curly and straight. From the description, we find that all the children are curly haired, indicating that curly hair is dominant over straight hair. Let us assume that the hair type gene is represented as 'C'. The father could have either of the two genotypes CC or Cc. The mother, being straight haired, would be homozygous recessive, cc. Assuming that all the children born to the couple are curly haired, the genotype of the father should be CC, that is, homozygous dominant. Children born to the homozygous dominant father (CC) and homozygous recessive mother (cc), will be heterozygous dominant (Cc) and will have curly hair. If the second scenario was true, where the father is heterozygous dominant (Cc), it is possible that at least one child born to the couple will have the recessive phenoype of straight hair.
