Download Name_________________________________ Biology-

Name_________________________________
Biology--Mr. Nelson
Monohybrid Crosses 2
The following chart gives you the letters assigned to different gene for four traits.
Trait
Dominant Gene
Seed Coat Shape
Recessive Gene
Round (R)
Smooth (r)
Pod Color
Green (G)
Yellow (g)
Plant height
Tall (T)
Short (t)
Brown (B)
White (b)
Seed Coat Color
Directions: Use punnett squares to predict the expected genotypic and phenotypic ratios in the
following monohybrid crosses.
1. Parent Genotypes; Gg x GG
Genotypic ratio of offspring
Phenotypic ratio of offspring
2. Parent Genotypes; Tt x Tt
Genotypic ratio of offspring
Phenotypic ratio of offspring
3. Parent Genotypes; Rr x Rr
Genotypic ratio of offspring
Phenotypic ratio of offspring
4. Parent Genotypes Rr x RR
Genotypic ratio of offspring
Phenotypic ratio of offspring
5. Cross a parent plant that is homozygous for green pods with a second parent plant that is
heterozygous for green pods.
Genotypic ratio of offspring
Phenotypic ratio of offspring
6.
Cross one homozygous tall parent plant with another short parent plant.
Genotypic ratio of offspring
Phenotypic ratio of offspring
7.
Cross a parent plant with white seeds with another parent that is heterozygous brown seeds.
Genotypic ratio of offspring
Phenotypic ratio of offspring
8. In squash plants, the gene for white fruits (F) is a dominant gene and the gene for yellow fruits
(f) is a recessive gene. If one parent with heterozygous white fruit is crossed with another parent
with yellow fruit. What are the expected genotypic and phenotypic ratios of the offspring.