Here's why:
* Basic unit of life: Cells are the fundamental building blocks of all living things.
* Self-sustaining: A single cell can perform all the essential functions necessary for life, including:
* Metabolism: Obtaining and using energy
* Growth: Increasing in size and complexity
* Reproduction: Creating new cells
* Response to stimuli: Reacting to changes in the environment
* Homeostasis: Maintaining a stable internal environment
While some organisms, like bacteria, are single-celled, multicellular organisms are made up of trillions of cells that work together to form tissues, organs, and systems.
