What is the definition of a cell in biological terms?

A cell is defined as the smallest unit of life because it can carry out all the necessary functions that characterize living organisms. This includes metabolic processes, growth, response to stimuli, and reproduction. Each cell is capable of maintaining homeostasis, which is essential for survival.

In multicellular organisms, cells form tissues, organs, and systems, but they are still fundamentally the smallest entities that can be considered alive on their own. Understanding this definition underscores the importance of cells as the foundational units of life, from the simplest single-celled organisms to complex multicellular organisms.

While tissues, organ systems, and assemblages of chromosomes are important biological concepts, they are not the defining characteristics of life at the cellular level.