2. 3 A Cell is the Smallest Unit of Life – Environmental Biology By the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory, which states that all living things are composed of one or more cells, that the cell is the basic unit of life, and that all new cells arise from existing cells
3. 3: A Cell is the Smallest Unit of Life - Biology LibreTexts By the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory, which states that all living things are composed of one or more cells, that the cell is the basic unit of life, and that all new cells arise from existing cells
What is life? (article) | Intro to biology | Khan Academy Living things are highly organized, meaning they contain specialized, coordinated parts All living organisms are made up of one or more cells, which are considered the fundamental units of life