What is the basic unit of a living organism?

The basic unit of a living organism is the cell. Cells are the fundamental building blocks of all living things, serving as the smallest structural and functional unit. They can exist as single-celled organisms, like bacteria, or as part of multicellular organisms, including plants and animals. Each cell contains vital components that allow it to perform essential life processes, such as metabolism, growth, and reproduction.

Cytoplasm, while important, refers to the gel-like substance within a cell that surrounds and supports the organelles, but it is not a living unit itself. The nucleus is a key organelle within cells that houses genetic material, but it does not represent the entirety of a living organism. Organs are made up of tissues, which are in turn composed of many cells, making them more complex than the basic unit of life. Thus, the focus on cells emphasizes their role as the primary building blocks of life in all organisms.