Bellwork: 12/1/15 Match the following terms to their examples 1.Homozygous dominant 2.Heterozygous 3.Dominant 4.Recessive 5.Phenotype A.Blue eyes B.Aa C.BB D.A E.a

Set up today’s page in your journal… Title: Dihybrid Crosses Page: 43 Date: Essential Question: How can I find the probability of a child inheriting more than one trait?

Dihybrid Cross: a cross that shows the possible offspring for two traits Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth In this example, we will cross a heterozygous individual with another heterozygous individual. Their genotypes will be: BbRr x BbRr

FOIL Method BbRr x BbRr Step 1: Find ALL possible gametes that can be made from each parent. Remember, each gamete must have one B and one R. DADMOM

DAD MOM Step 2: FOIL. Combine the FIRST, OUTER, INNER, and LAST letters for your possible gametes F O I L

Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth BbRr x BbRr BR bR br bR Br BR br Br Step 4: Fill in the Punnett Square (find the possible genotypes of the offspring) Step 3: Arrange all possible gametes for one parent on the top of your Punnett Square and the other parent on the side

Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth BbRr x BbRr BR bR br bR Br BR br Br BBRRBbRRBbRr BBRrBBrrBbRrBbrr BbRRBbRrbbRRbbRr BbRrBbrrbbRrbbrr BBRr

BR bR br bR Br BR br Br BBRRBbRRBbRr BBRrBBrrBbRrBbrr BbRRBbRrbbRRbbRr BbRrBbrrbbRrbbrr BBRr How many of the offspring would have a black, rough coat? How many of the offspring would have a black, smooth coat? How many of the offspring would have a white, rough coat? How many of the offspring would have a white, smooth coat? Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth

BR bR br bR Br BR br Br BBRRBbRRBbRr BBRrBBrrBbRrBbrr BbRRBbRrbbRRbbRr BbRrBbrrbbRrbbrr BBRr How many of the offspring would have black, rough coat? How many of the offspring would have a black, smooth coat? How many of the offspring would have a white, rough coat? How many of the offspring would have a white, smooth coat? Phenotypic Ratio= 9:3:3:1

Fractions Method Step 1: Split the traits for mom and dad BbRr x BbRr DAD MOM Bb Rr Bb Rr

Step 2: Create 2 punnett squares. Same letters together! DAD MOM DAD MOM B R r r R b B b Step 3: Fill in the punnett squares bb Bb BB Bb rr Rr RR

Step 4: Solve problems by multiplying fractions DAD MOM DAD MOM B R r r R b B b bb Bb BB Bb rr Rr RR How many of the offspring would have a black, rough coat? Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth 3 4 X 3 4 = 9 16

Step 4: Solve problems by multiplying fractions DAD MOM DAD MOM B R r r R b B b bb Bb BB Bb rr Rr RR How many of the offspring would have a black, smooth coat? Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth 3 4 X 1 4 = 3 16

Step 4: Solve problems by multiplying fractions DAD MOM DAD MOM B R r r R b B b bb Bb BB Bb rr Rr RR How many of the offspring would have a white, rough coat? Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth 1 4 X 3 4 = 3 16

Step 4: Solve problems by multiplying fractions DAD MOM DAD MOM B R r r R b B b bb Bb BB Bb rr Rr RR How many of the offspring would have a white, smooth coat? Fur Color: B: Black b: White Coat Texture: R: Rough r: Smooth 1 4 X 1 4 = 1 16

Practice in your notes… In pea plants, yellow seeds (Y) are dominant over green seeds (y), and rounded peas (R) are dominant over wrinkled peas (r). Cross a plant that is heterozygous for both traits with a plant that is homozygous recessive for both traits. Genotypes: What is the probability that the plant will be yellow and wrinkled? YyRr and yyrr

Y r r r R y y y yy YyYy YyYy rr Rr rr Rr How many of the offspring would have a yellow, wrinkled seed? 2 4 X 2 4 = 4 16

YyRr X yyrr YR yR yr Yr YyRryyRryyrr YyRrYyrryyRryyrr YyRrYyrryyRryyrr YyRrYyrryyRryyrr Yyrr or

Work on your Spongebob Dihybrid practice for the rest of class. We’ll finish tomorrow