All organisms are made of cells. In the hierarchy of biologist-ical organization, the cell is the simplest collection of matterthat can be alive. Indeed, many forms of life exist as single-celled organisms. More complex organisms, including plantsand animals, are multicellular; their bodies are cooperativesof many kinds of specialized cells that could not survive forlong on their own. Even when cells are pre-arranged into higherlevels of the organization, such as tissues and organs, the cell re-mains the unit of basic organism's structure and function.All cells are related by their descent from earlier.now cells. How-ever, they have been modified in many different ways duringthe long evolutionary history of life on Earth. But althoughcells can differ substantially from one another, they sharecommon features. In this chapter, we'll first examine the toolsand techniques that allow us to understand cells, then tourthe cell and become acquainted with its components.
Sedang diterjemahkan, harap tunggu..