2. Genetics- The Study of Heredity

3. Domestication of dogs may have been one of the earliest human experiments with genetics. Domestic dogs came from wild wolves!

4. Wolves with distinct traits were bred to eventually lead to a new breed – the domestic dog. Example of traits –Color –Size –Shape –Temperament –Hearing –Sense of smell

5. Trait- Characteristic that can be passed from parent to offspring.

6. Gregor Mendel Came up with one of the first clues to understanding inheritance. Austrian monk Began his work in 1860’s Used the garden pea plant Worked for more than 8 years on his experiments.

7. Reasons Mendel Chose the Garden Pea Plant Structure of the pea plant. Presence of 7 distinctive traits. Rapid reproductive cycle - 90 days

8. Purebred- An organism that receives the same genetic traits from both of its parents.

9. Hybrid- An organism that receives different forms of a genetic trait from each parent. “MUTT”

10. Dominant Trait- A form of a gene that is fully expressed when two different alleles are present. Bb

11. Recessive Trait- A form of a gene that is not fully expressed when two different alleles are present. Bb

12. What is an allele? A distinct form of a trait Example –Tall or Short –Purple or White –Curly or Straight

13. How do we represent alleles? Dominant trait- upper case letter –E–Ex. B, R, T, Y Recessive trait- lower case letter –E–Ex. b, r, t, y

14. Genes affect traits… Genes are sections of a chromosome that code for a trait.

15. Genotype- The genetic makeup of an organism. Genotype of a pea plant that is purebred for yellow peas would be written – YY Genotype of a pea plant that is hybrid for yellow peas would be written – Yy Key: Y- yellow y - green

16. Phenotype- The outward expression of the trait. What we see. The way an organism looks and behaves. YY & Yy would show yellow peas yy would show green peas.

17. Homozygous- Two alleles in a gene pair are identical. YY, yy, BB, bb, TT, tt

18. Heterozygous- Two alleles in a gene pair are different. Yy, Bb, Tt, Rr

19. Mendel’s Laws- basic rules of inheritance. #1 The law of segregation- Gene pairs separate when gametes form. Gamete- sex cell, sperm & egg

20. Law #2 The law of independent assortment- traits are inherited independently. That means, just because you have blonde hair does not mean you will have blue eyes.

21. Law #3 Law of dominance - the dominant allele is expressed and the recessive allele can be hidden.

22. Diploid- Cell with 2 of each kind of chromosome. The cell has the entire set of chromosomes.

23. Haploid- Cell with 1 of each kind of chromosome. Cell has half the number of chromosomes.