From multicellular and single-celled organisms to towering trees and hairy mammals, learn about living things in their ecosystems. Discover the science of classification, food webs, biomes, and meet the great thinkers who made these discoveries possible. Extraordinary photos and real-world examples invite readers to discover the world of biology, while an encyclopedic-entry-style format makes the text approachable and highly browsable. Final comprehension questions engage readers to check what they have learned to reenforce comprehension.