Clarify the incorrect options: Plant hormones are not composed solely of proteins; they include diverse chemical classes such as auxins, gibberellins, cytokinins, ethylene, and abscisic acid. Additionally, plant hormones are not transported exclusively through specialized glands, as plants lack glands; they are transported through vascular tissues or diffuse between cells. Animal hormones can influence gene expression, so the statement that animal hormones never influence gene expression is incorrect.