Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

The basic unit of living matter is a cell. Cells are the fundamental building blocks of life, capable of carrying out all necessary functions for an organism to survive, grow, and reproduce. They are the smallest unit that can be classified as living and can perform all vital processes, including metabolism, energy conversion, and genetic replication. In the context of multicellular organisms, cells organize into tissues and organs; thus, understanding the cell's role is crucial in biology. Each cell is surrounded by a plasma membrane and contains various structures called organelles that perform specialized functions. For example, the nucleus contains genetic material, while the cytoplasm is the gel-like substance within the cell where metabolic activity occurs. Other choices like the nucleus and cytoplasm refer to specific structures within a cell rather than the cell itself. Protoplasm, while being a term that refers to the living contents within a cell, is not as fundamental as the cell, which is the overarching unit. Therefore, the definition and function of a cell solidify its status as the basic unit of living matter.