• Complete Dominance• Codominance• Incomplete Dominance• Sex-Linked

X-linked: gene lies on X chromosome (males only have one copy of the gene)

Y-linked: gene lies on Y chromosome (only males have the gene)

Contributes to younger mortality rate in males

• Polygenic Traits

Phenotypic Expression Varies

Hemophilia

• Complete Dominance• Codominance• Incomplete Dominance• Sex-Linked

X-linked: gene lies on X chromosome (males only have one copy of the gene)

Y-linked: gene lies on Y chromosome (only males have the gene)

Contributes to younger mortality rate in males

• Polygenic Traits

Phenotypic Expression Varies

Hemophilia

• Complete Dominance• Codominance• Incomplete Dominance• Sex-Linked

X-inactivation disables one x-chromosome in each cell (females and males each only use one x-chromosome)

can lead to unique phenotypes in females

• Polygenic Traits

Phenotypic Expression Varies

Practice

• Sex-linked practice “Pipe Cleaner babies and genetic traits”. Complete and glue to page ___ of your notebook

• OR, do sex linked handout

Calico is a coat color found in cats, which is caused by a SEX-LINKED, CODOMINANT allele. B = black, R = orange, and BR = calico.The following genotypes are possible;  Female cats can be black XBXB, orange XRXR, or calico XBXR

Male cats can be black XBY or orange XRY

X Linked Genetics in the Calico Cat

• Complete Dominance• Codominance• Incomplete Dominance• Sex-Linked• Polygenic Traits

Controlled by more than one gene

Most common type ofexpression

Phenotypic Expression Varies

Pedigree Rules

• What is a pedigree?

 • *A pedigree is a chart that shows all

family members and how they are related. It follows certain rules and shows genotypes and phenotypes.

– Boys Shaded- Phenotype being “traced”

– Girls X deceased

Marriage same level=same generation

Mating w/o marriage Carrier (heterozygous)

Kids Adopted

Twins

• Draw a pedigree for your immediate family (mom, dad, step parents, siblings, etc)

Trait

Trait

Trait

traits

Trait

traits

Trait

Trait

Pedigrees

• Graphically shows the lineage of a disorder in a particular family

• Be able to tell if disorder is dominant, recessive, or sex-linked from a pedigree

• Be able to predict the chance that an indicated couple will have a child with the disorder

Pedigrees

Where would a gene be if it was autosomal?

Where would it be if it was sex-linked?

What gender is this person?

• Autosomal: Not sex-linked

Human Chromosomes

Pedigrees

Autosomal DominantHow can we tell?

• Autosomal: Not sex-linked

Human Chromosomes

Pedigrees

Autosomal RecessiveHow can we tell?

Pedigrees

Sex-LinkedHow can we tell?

Is the X-linked dominant or recessive?

Pedigree Analysis Case Study• Read family information• Put family name at the top of your whiteboard• Make a pedigree for the entire family• Label names of all family members that you know• Make a key for the possible genotypes and phenotypes of your trait. Label as many

individual genotypes on the pedigree that you can.• Shade in the people that have the trait • Identify the Patterns in the Pedigree and write the following answers on your

whiteboard:– Is the trait dominant or recessive?– Does the trait show up in every generation? Or, does the trait skip a generation?– Does the trait affect males/females equally? Or, Does the trait only affect males?

Or, only females?– Does your trait fit our model? (why or why not?) If not, what rule(s) need to

change, or what new rules do you need to explain how this trait is inherited?• YOUR PATTERN SHOULD SUPPORT YOUR ANSWER.•  • Get your teacher’s approval to chart all of this on paper.