Monohybrid practice problems
In pea plants, the traits below exhibit the following dominance patterns:
Trait:
Dominant
Expression:
Recessive
Expression:
1.
Seed shape (
R
) Round Wrinkled
2.
Flower color (
P)
Purple White
3.
Color of seed coat (
Y
) Yellow Green
4.
Form of ripe pods (
I
)
Inflated Constricted
5.
Color of unripe pods (
G
)
Green Yellow
6.
Position of flowers (
A
)
Axial Terminal
7.
Length of stem (
T
)
Tall Short
1. Record the genotypes for pea plants with the following descriptions (The first one has been done for
you):
a. gg A plant with yellow pods e. A plant heterozygous for green pods
b. A plant homozygous for round seeds f. A plant heterozygous for purple flowers
c. A plant homozygous for yellow seeds g. A plant with white flowers
d. A plant with green seeds h. A short pea plant
2. Complete the Punnett Square showing the cross between a pea plant with pure round seeds and a
plant with wrinkled seeds. Summarize the phenotypes and genotypes for the offspring.
Parental cross ______x_______ Genotypic Percentages:
Phenotypic Percentages:
3. A pea plant with pure yellow seeds is crossed with a plant with green seeds. Show all possible offspring
and their phenotypes and genotypes.
Parental cross ______x_______ Genotypic percentages:
Phenotypic Percentages:
4. A pea plant heterozygous for pod color is crossed with a pure green-pod plant. Show the cross and all
the phenotypic and genotypic ratios of the possible offspring.
Genotypic Ratio:
Phenotypic Ratio:
5. A heterozygous tall pea plant is crossed with a short pea plant. Show the cross and describe all
possible phenotypes and genotypes for the offspring.
Genotypic Ratio:
Phenotypic Ratio:
Name:
Date: Pd:
