Seeing Cells & One-Celled Organisms

A microscope that increases magnification by using more than one lens

• compound microscope

• cell theory

• simple microscope

Your body is made of ____ of cells. 

• thousands

• millions

• billions

The ___ can help us understand similarities and differences that exist between living organisms.

• cell theory

• cell membrane

• spontaneous combustion

Who created the compound microscope?

• Zacharias Janssen

• Antoni van Leewenhoek

• Robert Hooke

A structure inside a cell that directs the activities of the cell 

• nucleus

• cytoplasm

• cell membrane

The gel-like substance inside the cell membrane

• nucleus

• cytoplasm

• organelles

The very thin covering that surrounds a cell and allows certain substances to move into and out of the cell

• cell wall

• cell membrane

• cytoplasm

A living thing that has only one cell

• unicellular organism

• multicellular organism

A theory in biology that states that all organisms are made up of one or more cells, cells are the basic units of structure and function of all living things, and that all cells come from other cells

• cell theory

• compound microscope

• natural selection

Most living organisms on Earth have only ___ cell(s)

• 2

• 1

• 1,000,000,000