Congenital Deafness in Humans Is Due to the Homozygous Condition

Short Answer

Congenital deafness in humans is due to the homozygous condition of either or both of the recessive genes d or e . Both dominant D and E are necessary for normal hearing. Gene D/d affects the middle ear, while gene E/e affects the inner ear. It does not matter how good the normal inner ear (as indicated by E _) is; if there is something wrong in the middle ear, the individual is unable to hear. The same applies for the other gene. Give the phenotypic results of the following crosses:
(a) Dd EE x Dd EE
(b) Dd Ee x Dd Ee
(c) dd EE x DD ee
(d) Dd EE x Dd ee
(e) Dd EE x DD Ee