Question

which is a component of the modern cell theory that was not part of the original cell theory?
all organisms are made of cells.
all cells are similar in composition and metabolic activities.
all cells come from preexisting cells.
a cell is the basic unit of structure and function for all living things.

Explanation:

The original cell theory proposed by Schleiden and Schwann stated that all organisms are made of cells and a cell is the basic unit of structure and function for all living things. Virchow added that all cells come from pre - existing cells. The idea that all cells are similar in composition and metabolic activities is a part of the modern cell theory.

Answer:

All cells are similar in composition and metabolic activities.