Nov. 16, 2010.
Sex linked crosses
Blood type crosses
Incomplete dominance (blending phenotype ONLY)
Co-dominant (both traits show up)
Notes pages 8-9, and 12
Homework: Pages 63-72 and the extra credit and Lab 34
I. Sex linked Crosses
A. Genes are located only on sex chromosomes for sex-linked crosses
1. Mostly on the X chromosomes
This is how a sex-linked cross punnet square would look like:
There is no trait on the Y chromosome.
II. ABO Blood Groups
A. Types of blood
1. A= IAIA or IAi (DOMINANT)2. B=IBIB or IBi
3. AB= IAIB (CO-DOMINANT!)4. O= ii (RECESSIVE)
As Ms. Dillion says, If Sally had a baby, and she forgot who the father was, they could find the blood type of the baby, of Sally, and find the blood type of Sam, Joe, and Kevin.
Let's say Sally had 2 babies. One with blood type AB and one with O.
Sally's blood type is IBi
The father's blood type must be IAi. Congrats Kevin.
III. Incomplete Dominance
A. "Blends" together.
1. There is no dominant trait.
i. The "middle trait"
EX. If a red flower and a white flower cross, there will be pink flowers because there is no dominant color, they BLEND
A. Both traits show up
1. They do not blend.
i. The traits are both dominant
If a black feathered chicken crosses with a white feathered chicken and both white and black are co-dominant, then their chickies will have black and white feathers, not gray because THEY DO NOT BLEND. THEY ARE BOTH DOMINANT COLORS.