AP BIOLOGY

Detailed explanation-1: -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.

Detailed explanation-2: -The cell theory states that all living things are made up of cells, and living cells always come from other living cells. The gene theory states that the characteristics of living things are controlled by genes. Homeostasis is maintaining a constant internal environment. Evolution is a change in species over time.

Detailed explanation-3: -In biology, cell theory is a scientific theory first formulated in the mid-nineteenth century, that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells.

Detailed explanation-4: -Everything that lives is made up of cells. The second part of cell theory was that new cells are formed from preexisting cells. The third part is that all cells are similar. Finally, cells are the most basic units of life.