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: -The atom is the smallest and most fundamental unit of matter. It consists of a nucleus surrounded by electrons. Atoms combine to form molecules, which are chemical structures consisting of at least two atoms held together by a chemical bond.

Detailed explanation-4: -Answer and Explanation: The cell is the smallest unit of life because it is the most fundamental building block of every living organism.

Detailed explanation-5: -By the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory, which states that all living things are composed of one or more cells, that the cell is the basic unit of life, and that all new cells arise from existing cells.