- 1. Punnett Square for DDWW x ddww:
- Gametes from DDWW: DW, DW, DW, DW
- Gametes from ddww: dw, dw, dw, dw
- All offspring genotype: DdWw
- Punnett Square:
- Row/Column: DW | DW | DW | DW
- dw: DdWw | DdWw | DdWw | DdWw
- dw: DdWw | DdWw | DdWw | DdWw
- dw: DdWw | DdWw | DdWw | DdWw
- dw: DdWw | DdWw | DdWw | DdWw
- 2a. Probability of tall plants with purple flowers: 100% (or 16/16)
- Possible genotype(s): DdWw
- 2b. Probability of dwarf plants with white flowers: 0% (or 0/16)
- Possible genotype(s): None
- 2c. Probability of tall plants with white flowers: 0% (or 0/16)
- Possible genotype(s): None
- 2d. Probability of dwarf plants with purple flowers: 0% (or 0/16)
- Possible genotype(s): None
- 3. Punnett Square for BbRr x BbRr:
- Gametes from each parent: BR, Br, bR, br
- Punnett Square:
- Row/Column: BR | Br | bR | br
- BR: BBRR | BBRr | BbRR | BbRr
- Br: BBRr | BBrr | BbRr | Bbrr
- bR: BbRR | BbRr | bbRR | bbRr
- br: BbRr | Bbrr | bbRr | bbrr
- 4a. Probability of guinea pigs with black, rough fur: 9/16
- Possible genotype(s): BBRR, BBRr, BbRR, BbRr
- 4b. Probability of guinea pigs with black, smooth fur: 3/16
- Possible genotype(s): BBrr, Bbrr
- 4c. Probability of guinea pigs with white, rough fur: 3/16
- Possible genotype(s): bbRR, bbRr
- 4d. Probability of guinea pigs with white, smooth fur: 1/16
- Possible genotype(s): bbrr
Parent Tip: Review the logic above to help your child master the concept of trihybrid cross worksheet.
