The theory which states that all animals and plants are composed of cells and cell products is known as
A
Cell Theory
B
Atomic Theory
C
Bohr's Theory
D
None of the above
Correct Answer: Cell Theory
By the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory. The unified cell theory states that: all living things are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.