1. Genetics Review

2. 2/18 Warm-up
Set up Dihybrid Cross with these parents: -BbTt X BbTT

3. Traits found on the X chromosome are examples of ___________ traits
Sex-linked

4. The physical appearance of an organism, is the organism’s………
Phenotype

5. In Guinea pigs rough hair (R) is dominant of smooth (r)
In Guinea pigs rough hair (R) is dominant of smooth (r). Cross a hybrid for rough hair and a purebred with smooth. What would the cross look like?
Rr X rr

6. Incomplete Dominance W R
All RW = pink
(heterozygous pink) RW

7. Incomplete Dominance Cross 2 of the offspring

8. Codominance Both alleles are dominant and expressed
Ex. Erminette chicken feathers
Both black and white feathers

9. Codominance
Dad - type O (OO) X Mom - type AB (AB)

10. Sex-linked Trait Problem
Example: Eye color in fruit flies
(red-eyed male) x (white-eyed female) XRY x XrXr
Red=R
White=r
How many
Boys with red eyes?

11. Gregor Mendel
Father of genetics
Studied inheritance in PEA PLANTS

12. Purple P=Purple p=White Pp What is the Phenotype?
White What is the Genotype? pp

13. Phenotypic Ratio?
2:2
Yellow:Green

14. TD, tD
A woman who is heterozygous Tongue Roller (Tt) and Homozygous for Dimples (DD). What are the possible gametes?

15. RRyy

16. 9:3:3:1
Phenotypic Ratio? PPP

17. Polygenic Traits
Traits that involve multiple genes for a single trait. -Skin Color -Eye Color