1 Punnett Squares Developed by an English Biologist, Reginald Punnett in A method to predict the possible _______ of the ________ if the genotypes of the parents are given.

2 _________ Cross= crossing one trait Suppose both your parents have brown eyes and you also have brown eyes. Yet, your sibling has blue eyes. Would your sibling be an adopted sibling or your full-blooded sibling? How would you explain this?

3 If your parents have dominant genes… B = brown eye (dominant) b = blue eye (recessive) BB x BB (homozygous dominant) Brown = _______% Blue = _______%

4 If your parents have dominant and recessive genes… B = brown eye (dominant) b = blue eye (recessive) Bb x Bb (heterozygous) Brown = _______% Blue = _______%

5 If one parent is homozygous dominant and the other parent is heterozygous… BB (homozygous dominant) x Bb (homozygous recessive) Brown = _______% Blue = _______%

6 Punnett Squares: Blood Type A, B = dominant O = recessive Father is type A, homozygous; mother is type B, homozygous O = ______ % A = ______ % B = ______ % AB = ______ %

7 Punnett Squares: Blood Type A, B = dominant O = recessive Father is type A, heterozygous; mother is type B, heterozygous O = ______ % A = ______ % B = ______ % AB = ______ %

8 Punnett Squares: Blood Type A, B = dominant O = recessive Father is type O; mother is type AB O = ______ % A = ______ % B = ______ % AB = ______ %

9 Punnett Squares: Blood Type A, B = dominant O = recessive Father and mother are both type AB O = ______ % A = ______ % B = ______ % AB = ______ %

10 _________ Cross Crossing two traits Involves two different alphabet letters. (ex. A and B) Different alphabet letters represent different _____. Two letters for each trait. So, altogether, ____ letters for two traits per individual. AaBb

11 Dihybrid Cross How many possible combinations of _______ can you make? AaBb (heterozygous for both traits) -4 different letter combos or gametes -AB, Ab, aB, ab AABb (homozygous & heterozygous) -2 different letter combos or gametes -AB, Ab

12 Dihybrid Cross E = brown eye e = blue eye H = Brown hair h = blonde hair EeHh x EeHh

13 Dihybrid Cross E = brown eye e = blue eye H = Brown hair h = blonde hair EeHH x EEHh