Final answer:
While all cells originate from pre-existing cells through cell division according to cell theory, not all cheek cells are identical due to differential gene expression causing variation within genetically identical cells.
Step-by-step explanation:
The statement that all cheek cells are identical because all cells come from other cells through division is both true and false. It's true that all cells come from pre-existing cells through the process of cell division, as stated by the cell theory. This theory, which was developed in the mid-1800s by scientists including Rudolf Virchow, posits that cells are the basic building blocks of all living things and that new cells are produced only from existing cells.
However, the statement is also false in suggesting that all cheek cells are entirely identical. While each nucleated cell in a multicellular organism contains copies of the same DNA, and thus they are genetically identical, cells can exhibit different characteristics. This results from differential gene expression, where different sets of genes are turned on or off in response to various factors, leading to differences in the structure and function of cells even within the same organism.