Module 6

Module 6—Mendelian Genetics: The Transmission of Traits to the Next Generation

Lesson Summary

 

During this lesson you explored the following focusing question:

• What technologies exist to help explain and predict the inheritance of traits in breeding programs or family histories?

Pedigrees and Punnett squares are two excellent technologies that help visually represent inheritance. They can be used to predict the probabilities of future expressions of a trait, and can also help determine the mode of inheritance of that trait.

 

Lesson Glossary

 

autosomal dominant: these conditions appear in each generation in the pedigree, and cannot arise from two parents who did not have the condition

 

autosomal recessive: these conditions often skip a generation in a pedigree, and are indicated if two parents without the condition produce a child with the condition

 

autosomal: a condition is autosomal if the pedigree shows no significant difference in the number of each gender affected by the condition

 

pedigree: a picture of a family history of a genetic condition that indicates generation, gender, birth order in the generation, and parental and offspring relationships; the presence of the condition is indicated by a blackened-in symbol

 

X-linked dominant: a condition is X-linked dominant if the pedigree shows the condition is found in females significantly more than in males

 

X-linked recessive: a condition is X-linked recessive if the pedigree shows the condition is found in males significantly more than in females; carrier moms pass the allele to affected sons; affected sons cannot pass the allele to their sons, but pass it to their daughters, who in turn become carriers

 

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