Another look at Genetic Vocabulary

1. Another look at Genetic Vocabulary What is genetics? You learned about Gregor Mendel and what he discovered---so?

2. He looked at heredity: • The passing of physical characteristics from parents to offspring and wondered why? • How did it happen? • He discovered it was due to traits: a form of a characteristic such as color or height.

3. This is how we got to genetics. • Genetics is the study of heredity • Many men after Mendel also studied genetics and found out more and more information. • Today we have the whole human genone—that means we know which genes go to which trait in the body---!!!

4. What is a gene? • It is the factors that control a trait.

5. How does allele fit in there? • The alleles are different forms of a gene. • There are two alleles on each gene for a type of trait. • An organism’s traits are controlled by the alleles it inherits from its parents. • Some alleles are dominate while other alleles are recessive.

6. Dominate allele • This means that the trait carried will always show up. It would be represented by a capital letter—say, “H” for curly hair. • Even if the other gene was “h” for straight hair, the combination of “Hh” would have curly hair due to the dominate “H” trait.

7. Recessive allele • This trait would only show up in the organism if both alleles received were recessive. Why? • Recessive alleles are always hidden by a dominant trait. • Someone with straight hair would look like this: “hh”.

8. Can it be figured out? • Yes, pretty close if the alleles are known from the parents. These are set up on a Punnett Square. • The Dad is at the top, and the Mom is at the side. The two are combined and the results show what occurs.

9. Punnett squares can be very simple or very complicated. They are fun to do!! • Want to try one?

10. Here is how it is set up and put together:

11. Let’s try a simply one: • Draw this and try it.

12. Now—how about a larger one?

13. See, fun isn’t it? • Now let’s see how the class does with some common known traits and we’ll take a class total and make a table to see what’s what in here. • First you will count at your table only and then we will tally all info on the board for the whole class on dominant and recessive traits.

14. Ready---? • Let’s do it!