Plants provide us with food, clothing, shelter, and medicine. Between 10,000–12,000 years ago, groups of people gradually changed from a hunter-gatherer lifestyle to an agricultural way of life, intentionally saving and planting seeds from the best individual plants of crops that could be used as food. Encouraging the propagation of certain individuals artificially selected particular traits; in this way, humans have influenced the evolution of domesticated plants.

Cereals such as corn, wheat, and rice are members of the grass family, whose edible seeds (grains) have been critical for civilizations around the world. For centuries, humans and other animals have used plants for their medicinal properties. Today, natural-products chemists use a combination of laboratory techniques and information from folklore and herbal medicine to make compounds with effects similar to those of plant-derived compounds in the search for new and more effective drugs.

A plant is an organism that shares many characteristics with all organisms on earth, including an energy requirement and the ability to reproduce and respond to the environment. Plants also possess characteristics that make them different from other organisms, including being auotrophic, possessing cell walls composed of cellulose, and having open growth.

Botany is the scientific study of plants. Plants have a fascinating history and lore, and our national and world economies are based on them. Virtually everything we do is influenced by plants. Botanists learn about plants and the world by using a scientific method of investigation, a systematic way to describe and explain the universe, based on observing, comparing, reasoning, predicting, testing, and interpreting. Everyone uses a scientific method of investigation at times. Plant biotechnology is a multibillion-dollar industry that is changing our lives and society.