Which of the following terms refers to a basic unit of structure and function in living organisms?

The term "cell" is recognized as the basic unit of structure and function in living organisms. Cells serve as the fundamental building blocks for all forms of life, from the simplest single-celled organisms to the complex multicellular structures found in plants and animals. Each cell functions as an independent entity that can perform essential life processes, such as metabolism, energy production, and reproduction.

In contrast, tissues consist of groups of similar cells that work together to perform a specific function, while organs are formed from different types of tissues that collaborate to carry out more complex functions. Systems are composed of various organs that work together to achieve broader physiological objectives within the organism. Hence, while tissues, organs, and systems are vital components of the biological organization, they build upon the foundational role of cells.