IMMUNOLOGY

Detailed explanation-1: -A cell is the smallest unit that is typically considered alive and is a fundamental unit of life. All living organisms are composed of cells, from just one (unicellular) to many trillions (multicellular). Cell biology is the study of cells, their physiology, structure, and life cycle.

Detailed explanation-2: -All living things, or organisms, are made up of at least one cell. Some organisms, such as amoebas, are made up of only one cell and are therefore called unicellular organisms. On the other hand, multicellular organisms, such as humans, are composed of more than one cell.

Detailed explanation-3: -The cell theory is credited to the scientists, particularly, Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow. Theodor Schwann, a German physiologist, stated in his writings that all living things are composed of cells and the products of cells in their structures.

Detailed explanation-4: -The cell theory holds true for all living things, no matter how big or small, or how simple or complex. Since according to research, cells are common to all living things, they can provide information about all life.

Detailed explanation-5: -The three tenets of the cell theory are: All living organisms are composed of one or more cells. The cell is the basic unit of structure and organization in organisms. Cells arise from pre-existing cells.

Detailed explanation-6: -(iii) The cell theory means that all living objects consist of cells, whether reproducing or not.