Chapter 12.1.5 (Exam 3) Pedigrees

Question 1

What is a pedigree?

Answer 1

Family trees that show the occurrence of phenotypes in several generations of related individuals

Question 2

Why don’t pedigrees show clear proportions like the pea plants?

Answer 2

Humans have small families

Question 3

What are pedigrees used to determine?

Answer 3

Pedigrees can be used to determine whether a rare allele is dominant or recessive

Question 4

How are rare dominant alleles determined using pedigrees?

Answer 4

Every affected person has an affected parent
About half of the offspring of an affected parent are also affected

Question 5

How are rare recessive alleles determined using pedigrees?

Answer 5

Affected people can have two parents who are not affected

Only a small proportion of people are affected: about ¼ of children whose parents are both heterozygotes

Associated with a marriage of relatives

Question 6

How would it be possible for a rare dominant allele to appear without it being present in the P generation?

Answer 6

Mutation