Before the invention of microscopes, scientists did not know about cells. Some thought that life just appeared out of nowhere. Microscopes allowed scientists such as Schleiden and Schwann to see organisms under high magnification. After much study, which ideas became parts of the cell theory? Choose the three statements that apply.
A. Cells contain specialized organelles.
B. Cells are the basic units of life.
C. A group of similar cells makes up a tissue.
D. All living things are made up of cells.
E. All cells come from other cells.