Question

robert hooke placed a thin cross section from a cork oak tree under a microscope. he observed walled squares packed tightly together. hookes observation provides evidence for which principle of the cell theory?

all cells make energy from food.

all living things originate from a single cell.

all cells are physically and chemically identical.

all living things are made of one or more cells.

Explanation:

Hooke saw cell - like structures in cork. This shows living things (cork from tree) are made of cells.

Answer:

All living things are made of one or more cells.