Genetics Chapter 9

Vocabulary *Heredity – The transmission of traits from parents to offspring. * Traits- a specific characteristic of an organism (Example: Brown hair, blue eyes, multicellular) *Characteristic- a distinguishing mark, feature or attribute (Examples: hair color, eye color, cells)

Heredity Characteristic Trait

*Pure – Always produce offspring with that trait. *Strain – Describes all plants pure for a species. PURE STRAIN (These are 2 different types of flu strains)

*Allele –Each of several alternative forms of a gene ~represented by letters *Genotype-Genetic makeup of organism (you can not see someone’s genotype) *Phenotype- External appearance (the visible trait)

Allele

Principles of Genetics *Principle of Dominance & Recessiveness ~One factor in a pair may mask the other, preventing it from having an effect. *Principle of Segregation ~Each reproductive cell receives one factor for a trait, therefore 2 factors separate during egg & sperm formation. *Principle of Independent Assortment ~Factors for different characteristics are distributed to reproductive cells independently.

Which color is dominant? Which is recessive? What is the allele for green? What is the allele for yellow?

Click image for video- start at 5:25

Human Traits

Punnett Squares