Which of the following represents the smallest unit of life capable of replicating itself?

The correct answer is that a cell represents the smallest unit of life capable of replicating itself. Cells are the basic building blocks of all living organisms, and they possess the necessary machinery to reproduce. Each cell can perform essential life processes, such as metabolism, growth, and response to the environment. This capability allows cells to divide and create new cells through various processes like mitosis or binary fission, depending on whether they are prokaryotic or eukaryotic.

In the context of life forms, while tissues, organs, and organisms are made up of one or more cells and function together in a living system, they do not individually replicate. Tissues are groups of cells that perform a specific function; organs are structures made up of multiple tissues working together; and organisms encompass entire living entities, composed of numerous cells and complex interactions. Thus, the cell is the smallest unit that can independently replicate and sustain life.