The basic unit of structure and function of all living organisms is the cell.
Cells are often referred to as the building blocks of life. Each cell carries out vital processes necessary for maintaining life. They come in various shapes and sizes, adapting to different functions in organisms. For example, muscle cells are long and fibrous to facilitate movement, while nerve cells have extensions to transmit signals.
Every organism is made up of one or more cells. In unicellular organisms, like bacteria, a single cell performs all necessary life functions. In multicellular organisms, cells work together, forming tissues and organs, allowing for more complex functions and interactions. Therefore, understanding cells is crucial for studying biology, medicine, and the life sciences as a whole.