1. GENETICS INTRODUCTION Things you need to know to talk like a real geneticist…

2. Genes, Heredity and Mendel  Those things on our chromosomes that make us the way we are  We get all of them from our parents…called HEREDITY  Mendel’s experiments –1 Crossed two different true-breeding plants –2 Self-crossed the results from the first experiment

3.  Phenotype – the visible expression of the gene (Tall, short)  Genotype – the types of genes present

4. Let’s try!  Using the trait for plant height in pea plants, where tall is dominant over short, and using the letters T and t for the alleles, answer the following….

5.  Heterozygous – one of each type of gene – Aa  Homozygous – both genes the same – AA or aa

6. 1) What would be the symbol for a tall gene? 2) What would be the symbol for a short gene 3) What would be the genotype for a short plant? 4) What would be the two possible genotypes for a tall plant?

7.  5) What would be the phenotypes for the following genotypes: a. Tt b. TT c. tt

8.  6) What would be the genotype for a heterozygous individual?  7) What would be the genotype for a homozygous recessive individual?  8) What would be the genotype for a homozygous dominant individual?

9.  In pea plants, yellow pea color is dominant over green pea color. Using the letters G and g for the alleles, answer the following questions…

10.  9) What would be the genotypes for a. A green pea plant b. A heterozygous yellow pea plant c. A homozygous yellow pea plant

11. CONGRATULATIONS You are now ready to take some parents & make some kids!

12. Genetics exceptions…. Incomplete Dominance Polygenetic Traits One gene = more than 1 trait Environmental Factors

13. Incomplete Dominance  Neither allele is dominant over the other  Instead of one “beating” the other, the resulting phenotype is a “mix” of the two  Snapdragon example

15. Polygenetic Traits  Traits controlled by more than one gene  Can get more variety that way  Eye color is an example

16. One gene: more than 1 trait  White fur, blue eyed tiger

17. Environmental Factors  Even though your genes code for a certain trait, they need to be provided the correct environment to become “real”  Nutrition, health care, etc.  Video game example