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:

According to Mendel's laws of inheritance, when a purebred (homozygous) plant with one trait (yellow flowers) is crossed with a purebred plant with an alternative trait (white flowers), and all the offspring show the trait of one parent (yellow flowers in this case), the trait that appears in the offspring (yellow flower color) is the dominant trait. A recessive trait would not be expressed in the \(F_1\) (first - generation offspring) when crossed with a purebred dominant - trait organism. A heterozygous trait refers to an organism with two different alleles (\(Aa\)), which is not a property of a trait itself. A monohybrid trait is related to a cross involving a single trait, but it is not a description of the trait (dominant or recessive).

Answer:

Yellow flower color is a dominant trait.