Question

Purebred tall pea plants look the same as tall, heterozygous pea plants. Formulate a pollination experiment to identify whether a tall pea plant is purebred or heterozygous. Explain your answer in three to five sentences.

a. The phenotype of the offspring after self-pollination will determine the genotype of the parent plant.
b. The experiment involves cross-pollination with a known heterozygous tall pea plant.
c. The experiment involves self-pollination of the tall pea plant and observing the ratio of tall to short offspring.
d. To determine purity, the plant should be cross-pollinated with a short pea plant.

Answer 1

To identify if a tall pea plant is purebred or heterozygous, one should cross-pollinate it with a homozygous recessive short pea plant and observe the phenotype of the offspring.

Step-by-step explanation:

To determine whether a tall pea plant is purebred (homozygous dominant) or heterozygous for the tall trait, the correct approach is to cross-pollinate the tall pea plant with a known short pea plant (homozygous recessive). If the tall plant is purebred, all the offspring will be tall because the short plant can only contribute the recessive allele. However, if the tall plant is heterozygous, we would expect a mix of tall and short offspring, following a Mendelian 3:1 ratio.

Therefore, cross-pollination with a short pea plant and observing the phenotypes of the offspring is the best method to reveal the genotype of the tall parent plant.