The Cell

A. Cell Theory and Basic Cell Structure Definition: The fundamental principles stating that all living organisms are composed of cells, cells are the basic unit of structure and function, and all cells arise from pre-existing cells. Explanation: Cell theory forms the foundation of modern biology and explains that cells are the building blocks of all living things. Every organism, from simple bacteria to complex humans, is made up of cells that carry out essential life processes. This concept helps us understand how living systems are organized and function at their most basic level. The theory has three main components that have been developed through centuries of scientific observation and experimentation. Think of it as: Think of cells like bricks in a building - just as bricks are the basic units that make up different types of buildings, cells are the basic units that make up different types of organisms.