1. Dihybrid Crosses Notes Pages 270-271 chapter 11.3

2. Dihybrid crosses 1. Crosses involving 2 different traits
Dihybrid crosses 1. Crosses involving 2 different traits. Example: Height & color

3. ttgg TTGG FOIL METHOD FROM MATH TG TG TG TG tg
Parents:TTGG X ttgg To figure out what goes on the top and sides of the boxes.
FOIL METHOD FROM MATH
ttgg
TTGG
PREDICT RATIOS
TG TG TG TG tg

4. TG TG TG TG TtGg TtGg TtGg TtGg tg
All offspring have the genotype TtGg and their phenotype is Tall, and green

5. Parents:TtGg X TtGg To figure out what goes on the top and sides of the boxes.
FOIL METHOD FROM MATH
TtGg
TG Tg tG tg

6. TG Tg tG tg TG Tg tG tg

7. TG Tg tG tg TTGG TTGg TtGG TtGg TTGg TTgg TtGg Ttgg
In Dihybrid crosses when you cross a heterozygous with a heterozygous you get a 9:3:3:1 ratio
d/d d/r r/d r/r

8. Genotypes: Phenotypes:
T= Tall G= Green
t= short g= Yellow
Genotypes: Phenotypes:
TTGG tall,green
TTGg tall, green
TtGG tall, green
TtGg tall, green
TTgg tall, yellow
Ttgg tall, yellow
ttGG short, green
ttGg short, green
ttgg short, yellow