Plants may seem like simple organisms, but their complex systems for food production, reproduction, and protection make them some of the most highly adapted living things on the planet. From the arctic tundra to the tropical rainforests, plants dominate the land and produce the energy necessary to sustain life on Earth. This book investigates these amazing organisms and explores how they have provided cures for some of today's deadliest diseases. Plants may also play a vital role in helping to solve some of the world's most pressing problems, such as air pollution, nonrenewable resource consumption, and food shortages. From low-lying mosses to massive redwoods more than 30 stories high, plants all have one thing in common: They all began life as a single cell.