AP BIOLOGY

Detailed explanation-1: -The cell is the smallest structural and functional unit of living organisms, which can exist on its own. Therefore, it is sometimes called the building block of life. Some organisms, such as bacteria or yeast, are unicellular-consisting only of a single cell-while others, for instance, mammalians, are multicellular.

Detailed explanation-2: -The cell is the smallest unit of life that can divide, multiply, grow and respond to stimuli from the environment. The cell structure is colloidal. The vital signs called life, manifest itself in this colloidal environment called protoplasm.

Detailed explanation-3: -A cell is capable of carrying out all life processes, such as nutrition, excretion, respiration, etc. Hence it is called as the functional unit of life. The cell is the smallest unit of life and all the living beings are made up of cells. Hence a cell is called the structural unit of life.

Detailed explanation-4: -A cell is the smallest unit of a living thing. A living thing, whether made of one cell (like bacteria) or many cells (like a human), is called an organism. Thus, cells are the basic building blocks of all organisms.