Q.What structural and functional attributes must a cell have to be called a living cell?

To be called a living cell, a cell must be able to exist independently and carry out all the essential functions of life on its own.

• It should be capable of an independent existence, without depending on any other cell to survive.
• It should be able to perform all the essential functions of life by itself. …

The evidence for what defines a living cell comes from organisms that exist as a single cell. A unicellular organism demonstrates that one complete cell is genuinely enough to survive on its own, without needing to depend on any other cell. Such an organism manages two things simultaneously: it leads an independent existence, and it carries out all of the essential functions of life entirely by itself. …

Method: Deriving General Attributes From a Concrete Example

Abstract-sounding questions like 'what attributes must a thing have to count as X' are much easier to answer if you anchor your reasoning in a concrete real-world example that already satisfies the definition, rather than trying to reason about the abstract category directly. For 'what makes a cell living,' the natural anchor is a unicellular organism — a single-celled creature that is, indisputably, alive on its own.

Ask yourself: what does that single cell actually have, physically, and what does it actually do, functionally, that together let it survive with no help from any other cell? Splitting your answer into these two buckets — structural attributes (a boundary/membrane, its own genetic material, the internal machinery to make proteins and generate energy) and functional attributes (metabolism, growth, responding to stimuli, reproduction) — is what turns a vague impression ('it can live on its own') into the specific, gradeable list the question is actually asking for. …