studied in pea plants. If the problem does not state the inheritance pattern, look it up in your book or on the internet (e.g. google “images of Mendel’s peas”).

4. In Mendel’s peas, purple flowers are dominant to white flowers. If Mendel crossed a true-breeding strain of purple flowered peas with a true-breeding strain of white flowered peas (these are the parental generation—P), what genotypes and phenotypes would be present in the first generation (F1) of offspring? Make a Punnett square showing this cross.

5. Mendel allowed the offspring of the cross in #4 above to self-fertilize (pollen (male gamete) from one flower moves to the stigma (leads to the female gamete) of the same flower). This is essentially the same as crossing two heterozygotes together but with a lower level of genetic diversity in the offspring. Show a cross between two heterozygotes. In Mendel’s terminology, you are crossing two F1 plants together to get the F2 generation. What ratios of genotypes and phenotypes would be expected for the offspring of this cross (that is the F2 generation)? Make a Punnett square illustrating this cross and give the genotypic and phenotypic ratios expected.

6. In Mendel’s peas, inflated pod is dominant to constricted pod. If Mendel crossed a true-breeding strain of plants with inflated pods with a true breeding strain of plants with constricted pods, what genotypes and phenotypes would be expected in the F1 generation? What genotypes and phenotypes would be expected in the F2 generation?

7. White fruit is dominant to yellow fruit in squash. Pollen from a white-fruited plant that is known to be heterozygous is placed on the stigma of the flower of a yellow-fruited plant.

• What is the genotype of the white-fruited plant?

• What gamete(s) will this plant make?

• What is the genotype of the yellow-fruited plant?

• What gametes will this plant make?

• Make a Punnett square illustrating this cross.

• Give the expected genotypic ratio of the offspring of this cross.

• Give the expected phenotypic ratio of the offspring of this cross.

8. Tall is dominant to short height in pea plants. Pollen from a heterozygous plant is used to fertilize flowers on a short plant.

• What is the genotype of the heterozygous plant?

• What is the phenotype of this plant?

• What gamete(s) can this plant make?

• What is the genotype of the short plant?

• What is the phenotype of this plant?

• What gamete(s) can this plant make?