Dr. Smith's parents have normal hearing. However, Dr. Smith has an inherited form of deafness. Deafness is a recessive trait that is associated with the abnormal allele d. The normal allele at this locus, associated with normal hearing, is D. Dr. Smith's parents could have which of the following genotypes?

Dd and Dd

Explanation:

The genotype is the function of biology and it is the makeup of cells in human beings as well as in animals. It is the factor that determines the phenotype along with the inherited factors. The individual who has the same genotype does not mean to work the same or appear the same, because the environment is another factor that shapes the behavior and characteristics of a person. And it is also that the person who is the same as the same genotype. One genotype is specifically referred to as the one inherited characteristics of one of the interests and combinations of the allele that an individual carried. It is usually denoted with the words Bb where one B stands for allele and another b also stands for another allele.