Question

During an experiment, a scientist crosses a pea plant that has purple flowers with a pea plant that has white flowers. The plants that result from this cross in the F1 generation have both purple and white flowers. What can the scientist conclude?
White flowers are dominant over purple flowers.
Neither purple flowers nor white flowers are dominant.
The plants in the P generation were not true-breeding.
All the plants in the F2 generation will have purple flowers.

Answer 1

Neither purple nor white flowers are dominant.

Explanation: If one color were dominant, a cross of two true-breeding parents would give only the dominant phenotype in F1. Seeing both colors in the F1 indicates that neither allele completely masks the other (e.g., codominance), so you cannot call one color dominant.