1. Happy Thursday!
5 mins to finish up & turn in the “meiosis simulation” (make a baby) from yesterday
If you’ve finished, read page __________ in the text book on dihybrid crosses
Pick up a sheet of notes from the front

2. STEP #1: Record the alleles and the traits they encode.
Blue beetle color = ____
Green beetle color = ____
Polka dot pattern = ____
No polka dot pattern = ____

3. STEP #2: Write the parents’ genotypes.
____ ____ ____ ____ X ____ ____ ____ ____

4. STEP #3: Determine the 4 possible gametes for each parent.
Use distribution property from math class!
Alleles for the same trait must separate (Mendel’s Law of Segregation).
Parent 1: BbPp
Parent 2: bbpp

5. STEP #4: Write possible gametes along the top and side of a 4x4 Punnett square.

6. STEP #5: Fill in your Punnett square
STEP #5: Fill in your Punnett square. Put alleles of the same trait together, with dominant before recessive.

7. STEP #6: Write the 4 possible phenotypes, then count them using shapes.

8. STEP #7: Write the phenotypic ratio (not genotypic).