The Cell

The basic unit of life

Can you guess that cell type???

Macrophage killing bacteria

Nerve Cell

Human Cheek Cell

Plant (onion) Cells

Sperm and Egg Cells

Paramecium(single celled organism)

Amoeba(single celled organism)

Bacteria Cells

Cellular Variation• Cells come in numerous shapes and sizes.

Their shape is usually somehow related to their function.

• Some organisms like plankton, amoeba and bacteria are composed of a single cell. Bacteria cells do NOT contain a nucleus = prokaryotic

• Other, more complex organisms, are made of mnay different cells with a nucleus = eukaryotic

• Humans are made up of about 100 trillion cells!

Van Leeuwenhoek the “father of microscopy”

Robert Hooke + Cork = “Cells”

Times have changed, yet …

The Cell Theory

1. All living things are made of cells.

2. Cells are the basic unit of life.

3. All cells come from preexisting cells.

How big is a cell?

What size are the cells we looked at last class?

• Actual Size=• field of view ÷• estimate of # of specimens that fit across F.O.V