1. Genetics N’ Stuff

2. Who Came Up with This?
Gregor Mendel
Proposed theory of heredity
Traits are passed from parents to offspring

3. He worked with pea plants
tall
short

4. Why did the tall override the short?
Dominant= trait that is bossy
Recessive= trait that gets masked

5. Section 10.1 Summary – pages 253-262
Tall plant
Short plant
tall plant passes on “T” allele = letter
dominant over “t” allele T T t t T t
All tall plants T t
Section 10.1 Summary – pages

6. Why does each trait have 2 letters?
A letter is passed from each parent
Hello! Heredity

7. Homozygous- 2 same size letters HH or hh
Heterozygous= different size letters Hh

8. Physical trait= round snoot!!
If I have genotype Ww, and W=round snoot and w=pointy snoot, what will my phenotype be?
Physical trait= round snoot!!

9. Phenotype= physical trait
Genotype = letters or alleles

10. Let’s do an example with a punnett square!

11. If there are only brown dominant chickens and white recessive chickens, how could you get a red chicken?
Incomplete dominance

12. Incomplete= 2 phenotypes mix to make a medium trait
Codominance= when both phenotypes show up
Example= blood type

13. But what about height? There are way more than 2 or 3 sizes of person!
Polygenic Traits

14. Polygenic Traits
More than one allele controls it
Examples: height,

15. Traits can also be linked by 9sex
Only boys get color blindness
Hemophilia