Tshego is deaf with the following genotype (dd). She marries Katlego, who is also deaf (dd). If they have a child, which of the following possibilities is likely:

Question

Their child is expected to have normal hearing with a genotype of DD (two dominant genes)
Their child is likely to have normal hearing with a genotype of dd (two recessive genes)
Their child is also expected to be deaf and have a genotype of dd
Their child is also likely to be deaf and have a genotype of DD (two dominant genes)

Answer 1

Since both Tshego and Katlego have the genotype dd (homozygous recessive), it means they both express the recessive trait of deafness. When they have a child, the genotype of the child will be the result of inheriting one allele from each parent.

Both parents can only pass on the recessive allele (d), so the child's genotype will be:

• Parent (Tshego): d
• Parent (Katlego): d
• Child's genotype: dd

This means that their child will also have the genotype dd, which reflects the trait of deafness.

Therefore, the correct answer is:

Their child is also expected to be deaf and have a genotype of dd.