Chapter 1: Cells Section 1 Life Science

Do you Remember?  All living things are organized…  A Cell is the basic unit of structure in living things that carry out life processes.

Organisms depend on cells  Unicellular- single-celled organism

 Multicellular- organism made up of more than one cell

The History of the Cell  Scientists used their new invention, the microscope, to discover microscopic organisms.  Using the microscope, scientists were able to explore the world of cells…

Modern Microscopes  “What type of microscope did Robert Hooke use to discover cells?”

Discovery of Cells  In 1665, Robert Hooke used a compound microscope to look at a thin slice of cork. –Observed empty boxes that he named “Cells” –Cork came from an Oak Tree

Hooke’s Discovery

Discovery of Living Cells  Late 1600’s, Anton van Leeuwenhoek used a glass bead to look at pond water.  First to discover living single-celled organisms

Development of the Cell Theory  Cell Theory States: 1.All Living Things are made up of one or more cells. 2.Cells are the basic units of structure and function in living things that carry out life functions. 3.All cells come from other living cells.

Lab Activity  You will pretend you are Robert Hooke as you look through the microscope at a piece of cork and draw what you are viewing at the 3 different powers.

Lab Activity  Pre-Lab Questions: –What type of Microscope do we use in lab? –What are the three objective lenses on the Microscope? –Why must you be careful when using the High-Power Objective Lenses?

 Louis Pasteur studied microorganisms and the cell theory…  He Observed that spoiled milk contained BACTERIA!

Pasteur  Bacteria are single-celled organisms that can cause disease.  Developed Pasteurization which is a process that uses heat to kill bacteria.

Bacteria and Spontaneous Generation  So we know… Bacteria are single- celled organisms that can cause disease.  Where can bacteria be found???  Pasteur found microorganisms everywhere (air, water, soil, blood)

 While Pasteur was conducting research studies, scientists thought bacteria grew from nonliving materials… or they …  Spontaneously Appeared !!!! (Spontaneous Generation)

 Spontaneous Generation- the idea that bacteria grew from nonliving materials  What do you think???  What do you know???

Look at Text Pg 15  Disproved by …Pasteur’s Experiments  He showed that cells come from other cells… and confirmed the cell theory