Traits

Question 1

Autosomal dominant traits

Answer 1

both females and males are affected
all affected individuals have at least one affected parent
once the condition disappears from a branch on the pedigree it never returns
fathers and mothers can pass on the condition to both their sons and daughters

Question 2

Autosomal recessive traits

Answer 2

both males and females are affected
two unaffected parents can have an affected child
all the children of parents who both have the condition will be affected
trait can skip a generation

Question 3

X-linked dominant traits

Answer 3

a male with the trait passes it onto all his daughters and none of his sons
every affected individual has at least one parent with the trait
females are affected more than males
once the condition disappears from a branch on the pedigree it never returns

Question 4

X-linked recessive traits

Answer 4

affected females always produce affected sons
the daughters of affected males are always carriers
all the children with two affected parents will show the trait
more males are affected than females

Question 5

does the trait appear in each generation - yes

Answer 5

Are only males affected?
Yes: Y linked

No: when affected males have children with normal females do all daughters have the condition?
Yes: x-linked dominant
No: autosomal dominant

Question 6

does the trait appear in each generation - no

Answer 6

Do the fathers of affected females have the condition and is it more common in males?
Yes: x-linked recessive
No: autosomal recessive