Robert Hooke

• 1665 – Micrographia• First to identify

structure known as cells in cork

• Predicted that there are 1,259,712,000 cells in the human body

Anton van Leewenhoek

• 1676 – First to observe live cells

• 1683 – Discovers bacteria

Matthias Schleiden

• 1838- Suggests that all plants are comprised of multiple cells

• Also discovered the importance of the nucleus

Theodor Schwann

• 1839 – Suggests that all animals are made of many cells

• Also coined the term “metabolism”

The Cell Theory

• 1) All living things are made of at least one cell• 2) Cells are the basic units of life. • 3) Cells may develop as a result of

spontaneous generation

Rudolf Virchow

• 1855 – Suggests that cells must come from pre-existing cells

The Cell Theory Version 2.0

• 1) All living things are made of at least one cell

• 2) Cells are the basic units of life. • 3) Cells must develop from pre-existing

cells

CYTOLOGY

Cells By The Numbers

• 10,000 Trillion Cells per person (avg.)• 90%+ are not you• Hundreds of different cell types made of

100 million proteins. There are 200,000+ different types of these proteins. We know the exact form of 2% of these proteins

• Electrical activity of 0.1 volts/nanometer = same as a thunderstorm

• DNA attacked every 8.4 seconds

Cellular Unity & Diversity: How and Why?

Lab: Fundamentals of Light Microscopy

• Purpose: To develop facility with using the compound light microscope and to prepare specimens for viewing

• Methodology: Light microscopy

Watch Your Cords!

Part 2: Calculating Magnification

• Ocular = 10x• Objective = 4, 10 or 43x

• Total Magnification = ocular x objective

Part 2: Measuring Field of View

Approximating Cell Size

• To calculate approximate cell size, estimate how many cells lined end to end would cover the diameter of the field of view.

• Divide the field size by this estimated number of cells = appx. cell size (in um)

After centering, adjust light before attempting to focus

Part 4: Depth of Field

PART 5: Wet Mount Slide