Question

a purebred plant that has yellow flowers is crossed with a purebred plant that has white flowers. all the offspring have yellow flowers. which conclusion about yellow flowers is supported by these results?
○ yellow flower color is a dominant trait.
○ yellow flower color is a recessive trait.
○ yellow flower color is a heterozygous trait.
○ yellow flower color is a monohybrid trait.

Explanation:

When a purebred (homozygous) yellow - flowered plant is crossed with a purebred (homozygous) white - flowered plant, and all the offspring show the yellow flower trait. According to Mendelian genetics, the trait that is expressed in the \(F_1\) generation (first - generation offspring) is the dominant trait. A recessive trait would not be expressed in the \(F_1\) generation when crossed with a purebred dominant - trait organism. A heterozygous trait refers to an organism with two different alleles (\(Aa\)), but the question is about the nature of the trait (dominant or recessive), not the zygosity of an individual in a general sense. A monohybrid trait is related to a cross involving a single trait, but this does not explain why yellow is expressed over white.

Answer:

Yellow flower color is a dominant trait.