1. Nuray Ozdemir 7th Period, Science December 4,2008
Shrek and Fiona
Shrek and Fiona are going to have baby.
Fiona has blue eyes (bb). Her husband Shrek has brown eyes (BB) What percentage of their child will have brown eyes?
Nuray Ozdemir
7th Period, Science
December 4,2008

2. Setting up the Punnett Square
B B
Shrek Fiona b BB bb
Dominant = Brown eyes (BB)
Recessive = Blue eyes (bb)
Genotype Box
First create your table that has 4 boxes in total.
Place Shrek’s genes (BB) on top of the Punnett Square.
Place Fiona’s genes on the left side of the Punnett Square.
Phenotype Box

3. Solving Your Punnett Square
B B B B B B
Phenotype
Genotype
Brown Eyes BB
Blue Eyes bb b b b b b b
Multiply the top and left side letters and write them in the box.
Don’t forget dominant traits always comes first, then the recessive letter.
For the phenotype box only dominant picture is used.

4. Results Phenotypic Results
The percent the Shrek and Fiona will have brown eyes child is 100%.
Genotypic Results
The percent the Shrek and Fiona’s child will have Bb as genetic code for eye color is 100%.

5. Quiz 1. What was the dominant gene and the recessive gene?
The dominant gene was brown eyes (BB) and the recessive gene was blue eyes (bb).
2. Is recessive letter comes before the dominant letter when you write them inside the Punnett Square box?
No, dominant trait comes before the recessive trait.
3. What eye color does Fiona have?
Fiona have blue eyes.
4. What eye color would Shrek and Fiona’s child have if it had bb as a genetic code?
Child would have blue eyes.
5. What is the different between purebred and hybrid?
Purebred is having two identical genes for a trait (BB,bb). Hybrid is having two different genes for a trait (Bb).