1. Mr. Altorfer Science Traits and Inheritance Pages 120 to 125

2. Traits and Inheritance Genes: One set of instructions for an inherited trait. –E–Each parent g ives one set of genes to their offspring. –E–Each offspring then has two forms of the same gene for every characteristic –T–Tall plants genes could be TT, Tt or tt.

3. Alleles- The different forms of a gene. – Dominant alleles are shown with a capital letter. – Recessive alleles are shown with a lower case letter. – Remember TT, Tt or tt? Alleles

4. Phenotype Phenotype- The appearance of an organism. –E–Example: What do these organisms look like?

5. Genotype Genotype- The gene makeup of an organism. –E–Example: Remember the tall gene? TT, Tt, tt –A–All three of these combinations are a different genotype

6. Homozygous- When an organism has two dominant or recessive alleles. –Example: TT or tt (Pure Bred) Heterozygous- When an organism has a mixture of dominant and recessive alleles. –Example: Tt (Hybrid)

7. Punnett Square Punnett Square- A tool used to organize all the possible combinations of offspring from a set of parents.

8. As a result of this cross, what color will the offspring of these two birds be? What is the phenotype of each of the offspring? What is the genotype of each of the offspring?

9. Incomplete Dominance Incomplete Dominance- Occurs when one trait is not completely dominant over another trait.

10. This flowers parents were red and white. No one color red, or white is dominant. Each color is expressed or shown.

11. Many Genes, One Trait Some traits such as the color of your skin, hair and eyes are the result of several genes acting together. Therefore it is difficult to tell if some traits are the result of dominant or recessive genes.