General Biology II: Monohybrid Cross
Activity No. 3.3. Monohybrid Crosses
(Dry Laboratory)
Instruction: Using the provided PUNNETT SQUARES, determine the genotypes and phenotypes of each
cross. SHOW YOUR SOLUTION IN A SCRATCH AND HAVE A PICTURE OF IT. (40
pints)
1. In pea plant, yellow pea pod is dominant over green pod. A plant with heterozygous yellow pea pod
is crossed to the plant with homozygous green pea pod. What would be the % probability to have an
offspring with yellow pea pod? Use letter “G and g” for your genotype.
1.A. Parental Genotypes
1.B. Genotypic Ratio:
1.C. Phenotypic Ratio:
1.D. Answer:
2. Tall plant is dominant over dwarf plant. A homozygous tall plant is crossed with a heterozygous tall
plant. What would be the probability in fraction to produce an offspring with heterozygous dominant
trait. Use letter “T and t” for your genotype.
2.A. Parental Genotypes
2.B. Genotypic Ratio:
2.C. Phenotypic Ratio:
2.D. Answer:
3. Purple flower is dominant over white flower. A plant breeder would like to cross two plants that are
both heterozygous for a trait. What would be the percent probability to produce offspring(s) with
purple flowers regardless if the resulting traits are homozygous or heterozygous? Use letter “F and
f” for your genotype.
Name:
Date:
Gr./Strand/Sec.:
Teacher:
