sect+review+7-1

Answers: 1. All Living things are composed of cells. Cells are the basic units of structure & function in living things. New cells are produced only from existing cells.

2. Prokaryotic cells are generally smaller and simpler than eukaryotic cells. Eukaryotic cells contain a nucleus; prokaryotic cells do not. Eukaryotic cells generally contain dozens of structures and internal membranes.

3. A TEM is produced by passing electrons through an extremely thin sample. An SEM is produced by scanning a pencillike beam of electrons over the surface of an object.

4. A cell membrane and DNA

5. The microscope was essential in that development because it allowed biologists to observe cells in living things.