10.2.A1:  Completion and analysis of Punnett squares for dihybrid traits.

• Determine possible allele combinations in gametes for crosses involving two genes.

• Use correct notation to depict a dihybrid cross between two unlinked genes.

• Construct a Punnett square to show the possible genotype and phenotype outcomes in a dihybrid cross. 

10.2.S1:  Calculation of the predicted genotypic and phenotypic ratio of offspring of dihybrid crosses involving unlinked autosomal genes.

• Determine the predicted genotype and phenotype ratios of F1 and F2 offspring of dihybrid crosses.

10.2.S3:  Use of chi-squared test on data from dihybrid crosses.

• Calculate a chi-square value to compare observed and expected results of a dihybrid genetic cross.

• Using the df and critical chi-square value, determine if there is a significant difference between obser

Introduction to unlinked dihybrid crosses

Modeling dihybrid crosses with coins

Two gene crosses practice

Additional dihybrid practice

ONE OF THE FOLLOWING LABS

Dihybrid corn lab

or

Fast plant dihybrid lab (Carolina guide)

A&B:  Epistasis gene interactions

A&B:  Trihybrid

Trihybrid cupcakes

Rule of multiplication (a simpler way)

Beyond dihybrid practice

Cat Genetics “Escape Room”

• Slides

• #5 - dihybrid

• #6 - many genes

10.2.U4:  The phenotypes of polygenic characteristics tend to show continuous variation .

• Explain polygenic inheritance using an example of a two gene cross with codominant alleles.

• State that a normal distribution of variation is often the result of polygenic inheritance.

• State example human characteristics that are associated with polygenic inheritance.

 10.2.A3:  Polygenic traits such as human height may be influenced by environmental factor

• Outline two example environmental factors that can influence phenotypes.

• Compare continuous to discrete variation.

Polygenics notes

Polygenetic handwritten notes 1

Polygenetic handwritten notes 2

Human traits - discrete or continuous?

idea of OMNIGENIC 

Modeling polygenics activity

Polygenics data submission form

Modeling polygenics data

Science of skin color notes

HHMI Biology of Skin Color

HHMI student handout

Reading:  Black woman with white parents

Reading: India fare skin 

Reading:  Genetics of skin color

Reading:  origin of dark and light skin

SciNetLink:  Race and Genes

A&B:  gene variants reveal the evolution of skin 

A&B:  Complex Architecture for Skin Pigmentation 

VOX:  the myth of race

TEd Ed:  The science of skin color TED:  Race and Genetics | Dr Allen Gathman

Science in the Classroom:  skin color

RACE - The Power of an Illusion 

Smithsonian LL Collection on Skin Color

Additional Teacher Resources

Analyzing height genetics activity

10.1.NOS:  Making careful observations- careful observations and record keeping turned up anomalous data that Mendel’s law of independent assortment could not account for. Thomas Hunt Morgan developed the notion of linked genes to account for the anomalies.

• Describe the experiment of Bateson and Punnett that led to results that did not support Mendel’s law of independent assortment.

• Describe the trends and discrepancies that led Morgan to propose the idea of linked genes.

10.2.NOS:  Looking for patterns, trends and discrepancies- Mendel used observations of the natural world to find and explain patterns and trends, Since then, scientists have looked for discrepancies and asked questions based on further observations to show exceptions to the rules.  For example, Morgan discovered non-Mendellian ratios in his experiments with Drosophila.

• Describe the trends and discrepancies that led Morgan to propose the idea of linked genes.

10.2.A2:  Morgan's discovery of non-Mendelian ratios in Drosophila.

• Describe how Morgan discovered the relationship between eye color and sex in Drosophila.

THM Discovery notes

THM Discovery Check for Understanding

Scitable Discovery and Types of Linkage

Modeling THM Crosses

10.2.U2:  Gene loci are said to be linked if on the same chromosome.

• Define autosome and sex chromosome.

• Describe what makes genes “linked.”

Linked genes slides

Linked genes handwritten notes 

Linked vs unlinked handwritten 

Scitable linked genes

Linked genes practice problems

More practice problems

10.2.S2:  Identification of recombinants in crosses involving two linked genes.

• Use correct notation to show alleles of linked genes.

• Construct a Punnett square to show the possible genotype and phenotype outcomes in a dihybrid cross involving linked genes. 

• Explain how crossing over between linked genes can lead to genetic recombinants.

Crossing over in linked genes

Summary comparing unlinked vs linked genes

Mega genetics flow chart

Group review slides

More practice problems (answers)

1-pager

Practice problems with Chi-Square (Rogers)

Final knowledge audit