The invention of the microscope led to the discovery of the cell by Robert Hooke. While looking at cork, Hooke observed the box-shaped structures, which he called "cells" because they reminded him of the cells (rooms) found in monasteries. This discovery led to the development of the cell theory. Credit for developing the cell theory is usually given to two scientists. Theodor Schwann and Matthias Schleiden. The cell theory was then proposed by Theodor Schwann in 1839. There are three parts to this theory: living organisms are made up of cells, cells are the basic structural unit of all organisms, and all cells come from pre-existing cells. Which of these is supported by the tenets of the cell theory? Select ALL that apply. les )) A) Energy flow occurs within cells. B) Mitosis produces identical daughter cells. C) Living organisms can be unicellular or multicellular. D) DNA is copied and passed between cells during cell division. E) Single-celled bacteria grow and then divide in half to make new bacteria.​