pedigrees

Question 1

what is a pedigree

Answer 1

a diagrammatic representation of a family tree that is used to map genetic traits and diseases

Question 2

determining recessive pedigrees

Answer 2

• low numbers
  -unaffected parents have affected children
  -skips generations

Question 3

determining dominant pedigrees

Answer 3

• found in every generation (remembering there may be blank sections)
• affected parents have unaffected children
  -an affected individual must have at least one affected parent

Question 4

determining autosomal pedigrees

Answer 4

• equal numbers (usually) of males VS females affected
• affected females do not have to have an affected father

Question 5

sex linked recessive

Answer 5

• usually more males affected
• affected females MUST have an affected father
  -affected females have ALL affected sons

Question 6

if a child has an autosomal dominant trait, what can you say about the parents?

Answer 6

at least one parent must have the trait

Question 7

if 2 parents have an autosomal dominant trait, what can you say about the children?

Answer 7

each child has a 50-50 chance of inheriting the trait from 1 parent and a 50-50 chance not inheriting it

Question 8

if 2 parents have an autosomal recessive trait what can you say about the children?

Answer 8

all of their children will be affected

Question 9

if 2 parents do not have an autosomal recessive trait, what can you say about their children?

Answer 9

if both parents are heterozygous children will have a 25% chance of being affected, otherwise children will not be affected.