A woman with severe discoloration of her tooth enamel has four children with a man who has normal tooth enamel. Two of the children, a boy (Bob) and a girl (Gladys) have discolored teeth. Each has a mate with normal tooth enamel and produces several children. Gladys has 6 children, four boys and two girls. Two of her boys and one of her girls have discolored enamel. Bob has seven children, four girls and three boys. All four of his daughters have discolored enamel, but all his boys have normal enamel. a. Draw the pedigree for this family, indicating which individuals are affected with discolored enamel. b. Explain the inheritance of this condition.

 a. To draw the pedigree, we assign shapes and annotations as follows: - Circle: Female - Square: Male - Filled shape: Affected individual - Empty shape: Unaffected individual - Half-filled shape: Carrier (if the mode of inheritance includes carriers)

Here's a simple textual representation of the pedigree:

``` Grandmother (affected) Grandfather (unaffected) | | ----------------------------------------- | | | | Bob(affected) Gladys(affected) Child Child | | ------------ ----------------------- | | | | | | | | | | | | a a u u u u a u a u u u ``` (Letters: a - affected, u - unaffected)

In this simplified pedigree, it's clear that Bob has seven children (4 daughters all affected, 3 sons all unaffected), and Gladys has six children (3 affected, 3 unaffected).

b. To explain the inheritance of discolored enamel based on the given pedigree, several patterns emerge: - The condition seems to affect males and females equally, suggesting it is not sex-linked. - Bob and Gladys both have the discolored enamel, yet at least one parent has normal enamel, suggesting the condition could be inherited in an autosomal dominant fashion. - All of Bob's daughters being affected suggests the gene causing discoloration is located on an autosome, and if Bob also has a copy of a normal gene, then his daughters must receive the affected gene from him (as they would receive only his X chromosome). This also indicates that the condition is not X-linked dominant as his sons do not show the phenotype. - However, because not all of Gladys's children are affected, this suggests the gene for tooth discoloration could be a dominant gene with incomplete penetrance or possibly a dominant gene with variable expressivity.

Based on these observations, we can infer that the gene for discolored enamel is likely an autosomal dominant gene with variable expressivity or incomplete penetrance.