Download Punnett Squares Worksheet

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Class: ______________
Assn. # ______________
Punnett Squares Worksheet 2
The follow chart lists genes and traits for Pea Plants. Use the chart to answer the questions that
follow.
Trait
Dominant Allele
Recessive Allele
Pod Shape
Smooth (N)
Wrinkled (n)
Pod Color
Green (G)
Yellow (g)
Plant Height
Tall (T)
Short (t)
1. Nn x NN
a. Create a Punnett square to show the possible offspring
b. Write the possible genotypes of the offspring as a fraction
c. Write the possible phenotypes of the offspring as a fraction
2. gg x GG
a. Create a Punnett square to show the possible offspring
b. Write the possible genotypes of the offspring as a fraction
c. Write the possible phenotypes of the offspring as a fraction
3. Gg x Gg
a. Create a Punnett square to show the possible offspring
b. Write the possible genotypes of the offspring as a fraction
c. Write the possible phenotypes of the offspring as a fraction
4. A plant that is heterozygous for plant height is crossed with another heterozygous plant.
a. Genotype of parents: ________________ x _____________
b. Create a Punnett square to show the possible offspring
c. Write the possible genotypes of the offspring as a fraction
d. Write the possible phenotypes of the offspring as a fraction
5. A pea plant that is heterozygous for height crosses (female) with a plant that is homozygous
recessive for height (male). For the alleles, use the table at the top of Genetics Practice #4.
a. Female Parent (Ovule):
b. Male Parent (Pollen):
i. What is the genotype?
i. What is the genotype?
ii. What is the phenotype?
ii. What is the phenotype?
c. Set up a Punnett square to determine the genotypes of the offspring.
d. What percentage of plants would be tall?
e. What percentage of plants would be short?
6. A pea plant that is homozygous dominant for pea pod shape (female) crosses with a plant that
is homozygous recessive (male). For the alleles, use the table at the top of Genetics Practice #4.
a. Female:
b. Male:
i. What is the genotype?
i. What is the genotype?
ii. What is the phenotype?
ii. What is the phenotype?
c. Set up a Punnett square to determine the genotypes of the offspring.
d. What percentage of pea pods will be smooth?
e. Can any of the pea pods be wrinkled? Why or why not?
7. Tongue rolling is a genetically inherited trait. Tongue rolling is dominant to non-rolling. A male
who is heterozygous for the tongue-rolling gene mates with a female who is homozygous
recessive for the tongue-rolling gene.
a. What letter will you use for the dominant allele?
b. What letter will you use for the recessive allele?
c. Mother:
d. Father:
i. What is the genotype?
iii. What is the genotype?
ii. What is the phenotype?
iv. What is the phenotype?
e. Set up a Punnett square to determine what genotype their children would have.
f. What are the genotypes of the children?
g. Statistically, what is the chance that their first child will be able to roll his/her tongue?
h. Is it possible for the couple to have five children who all are not able to roll their tongue?
Explain using at least 2 sentences.