Using pedigrees to determine patterns of inheritance

What type of trait is shown above? A. sex-linked B. autosomal dominant C. autosomal recessive

How do you know this is a sex-linked trait?

Sex linked traits: - more common is males Sex linked traits: - more common is males. - the son gets the trait from mom.

What is the clue that this is a recessive trait?

Recessive traits: - if both parents have it, all the children will have it. -if both parents do not have it, but a child does, the parents were hybrid

This disease is autosomal dominant This disease is autosomal dominant. What is the genotype of the first generation female with the trait?

Cystic Fibrosis – recessive disease -caused by a mutation on chromosome 7 -causes excessive mucus to build up in the lungs -frequent pneumonia -individuals often don’t live past 40 Huntington’s disease - dominant trait -symptoms don’t begin until 30’s or 40’s -caused by a genetic defect on chromosome 4. -as the disease is passed along in families, symptoms develop at younger and younger ages. symptoms include: quick, sudden, sometimes wild jerking movements of the arms, legs, face, and other body parts, dementia