HUMAN HEREDITY

EQ: What can a pedigree tell you about the

inheritance of a trait?

HUMAN HEREDITY

Field Mouse

Karyotype: a picture of chromosomes grouped in pairs (homologous chromosomes)

Can tell you #’s of

chromosomesSexDisjunctions,

major deletions

BEYOND MENDELIAN HEREDITY Genes that are said to have 3 or

more possible alleles are said to have multiple allelesExample: human’s ABO blood types

SEX-LINKED DISORDERS Genes on either

of the sex chromosomes called sex-linked genes

Most on the X chromosome so called X-linked genes & disorders in them called X-linked disorders

Most X-linked disorders are recessive traits

Males have 1 X so we see whatever allele the male has expressed

X-LINKED DISORDERS1. Colorblindness 2. Duchenne

Muscular Dystrophy

3. HEMOPHILIA

PEDIGREES Chart that

shows the relationships w/in a family

Can be used to infer a family member’s genotype

PEDIGREE KEY Circles =

Females Squares = Males

If circle or square shaded = trait expressed

If circle or square not shaded = trait not expressed

Horizontal Line = Marriage

Vertical Line = Offspring

PEDIGREE PROBLEMS - 1

PEDIGREE PROBLEM - 2

PEDIGREE PROBLEM - 3

PROBLEM SOLVING PAGE 343 OF BOOK PAGE IN NOTEBOOK