Which of the following describes qualitative traits?

Qualitative traits are characterized by several key features that set them apart from quantitative traits. The definition encompasses traits that are controlled by one or a few genes, which means that they have a relatively simple genetic basis. This simplicity allows for clear distinctions between different phenotypes, as these traits often exhibit variation in discrete classes or categories rather than on a continuous scale.

For example, in a plant, qualitative traits might dictate characteristics such as flower color, where you might have distinct categories like red, blue, or yellow, as opposed to a gradual gradient of color. Additionally, these traits can influence factors such as leaf size, flower shape, or fruit type, further emphasizing their control by genetic factors.

Therefore, it is accurate to state that qualitative traits include all the aspects mentioned—being controlled by one or a few genes, demonstrating variation in discrete classes, and impacting specific characteristics like color and leaf size. This comprehensive understanding helps to classify and predict traits in plant breeding and genetics effectively.