Name_____________________

Genetics Problems

1. In the common pea, Pisum sativum, the alleles for tall plants, yellow seeds and round seeds D, G, and W respectively are all dominant over the alleles for dwarf plants green seeds, and wrinkled seeds d, g, and w.

1. Write the symbol for a tall plant that is heterozygous
2. Write the symbol for a wrinkled seed
3. Write the symbol for a homozygous yellow plant
4. Write the symbol for a heterozygous round seeded plant
5. Write the symbol for a green seed

2. In the pea an experiment is conducted in which a heterozygous yellow plant is cross pollinated with pollen from a green plant.  Give the genotypic and phenotypic ratio for the outcome for the experiment.

3. If a plant YyWw is crossed to a plant that is YyWw what will be the phenotypic ratio for this cross?

4. If a plant is DdWwyy, what possible combinations of these genes may occur in the pollen?

If a plant is DdWwYy what possible combinations of these genes may occur in the pollen?

5. A male fruit fly with the genotype +/sc was mated to a female fly with +/sc.  What will be the genotypic and phenotypic ratio for this experiment?

6.  A male fruit fly +    +          was mated to a female fruit fly      +     +

                            ry    vg                                                               ry    vg

what will be the outcome of this cross?  Give only the phenotypic ratio.

7. Write the genotype for a fruit fly that is heterozygous for apterous wings.
8. Write the phenotype for a fruit fly that is L/+
9. Write the genotype for a fruit fly that is heterozygous for Bar eyes.
10. Write the genotype for a fruit fly that is homozygous for lozenge eyes
11. Write the phenotype for a fruit fly that is homozygous for curly wings.
12. Write the genotype for a fruit fly that is homozygous for singed bristles