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Read ModeChapter 1: Introduction to Cell Biology
1.1 What is a Cell?
The cell is the basic structural and functional unit of all living organisms. Every living thing, from the smallest bacterium to the largest whale, is made up of one or more cells.
Cells were first discovered by Robert Hooke in 1665 when he observed cork under a microscope. The term 'cell' comes from the Latin word 'cella,' meaning small room.
1.2 Types of Cells
There are two main types of cells: Prokaryotic cells are simple cells without a nucleus, while Eukaryotic cells are complex cells with a nucleus.
Prokaryotic cells include bacteria and archaea. They lack membrane-bound organelles and their genetic material floats freely in the cytoplasm.
Eukaryotic cells are found in plants, animals, fungi, and protists. They contain a nucleus that houses DNA, along with various organelles.
1.3 Cell Theory
The cell theory states that all living organisms are composed of cells, the cell is the basic unit of life, and all cells arise from pre-existing cells.
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