Dihybrid Cross Worksheet
1. Set up a punnett square using the following information:
• Dominate allele for tall plants = D
• Recessive allele for dwarf plants = d
• Dominate allele for purple flowers = W
• Recessive allele for white flowers = w
• Cross a homozygous dominate parent
(DDWW) with a homozygous recessive parent
(ddww)
2. Using the punnett square in question #1:
a. What is the probability of producing tall plants with
purple flowers?
Possible genotype(s)?
b. What is the probability of producing dwarf plants
with white flowers?
Possible genotype(s)?
c. What is the probability of producing tall plants with
white flowers?
Possible genotype(s)?
d. What is the probability of producing dwarf plants
with purple flowers?
Possible genotype(s)?
3. Set up a punnett square using the following
information:
• Dominate allele for black fur in guinea pigs = B
• Recessive allele for white fur in guinea pigs =b
• Dominate allele for rough fur in guinea pigs =
R
• Recessive allele for smooth fur in guinea pigs
= r
• Cross a heterozygous parent (BbRr) with a
heterozygous parent (BbRr)
4. Using the punnett square in question #3:
a. What is the probability of producing guinea
pigs with black, rough fur?
Possible genotype(s)?
b. What is the probability of producing guinea
pigs
with black, smooth fur?
Possible genotype(s)?
c. What is the probability of producing guinea
pigs
with white, rough fur?
Possible genotype(s)?
d. What is the probability of producing guinea
pigs
with white, smooth fur?
Possible genotype(s)?
