Characteristics of Living Organisms

Organization

Metabolism

Respond to Stimuli

Reproduce

Evolve

Living Things are Organized

(Cell Theory)• all living things are composed of

cells• cells are the basic units of life• cells are produced from other

cells

Robert Hooke observed the First Cells

• cork through an early microscope- illustration shown on the left.

• Hooke called the individual units cells, after the monk’s rooms in a monastery.Source:

http://www.ucmp.berkeley.edu/history/hooke.html

Cork Cells

Compare the photograph of cork cells viewed through a modern light microscope to Hooke’s drawing.

Source: http://biology.clc.uc.edu/Fankhauser/Labs/Cell_Biology/Cells_Lab/cork_100x_PA021953c.JPG

Plant Cell Light Microscope

Source: http://www.umanitoba.ca/faculties/science/biological_sciences/lab3/images/lightplt.jpeg

Animal Cell Light Image

Source: http://www.umanitoba.ca/faculties/science/biological_sciences/lab3/images/lightani.jpeg

Animal Cell EM Image

Source: http://www.umanitoba.ca/faculties/science/biological_sciences/lab3/images/eukanimal5.jpeg

Animal Tissue

Source: http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20Laboratory/animal%20tissues/img001.jpg

Plant Tissue

Source: http://ccollege.hccs.cc.tx.us/instru/Biology/AllStudyPages/Cells/Images/ELODIA400_labeled.jpg

What two structures do plant cells have that animal cells lack?

The cell is the basic unit of life.

• Anton van Leeuwenhoek (1632-1723)

Single Cell Life Form

Source: http://www.umanitoba.ca/faculties/science/biological_sciences/lab3/images/bacillus.gif

Cells come from cells.

• Rudolf Ludwig Karl Virchow (1821 - 1902)

so…to review cell theory

1. All life forms are made from one or more cells.

2. Cells only arise from pre-existing cells.

3. The cell is the smallest form of life.

cellstissuesorganssystems

individualspopulationscommunitiesecosystemsbiosphere

Living Things Metabolize

• Metabolism is the sum of all of the chemical and energy transformations that take place in an organism.

Homeostasis is the maintenance of internal conditions within certain boundaries.

Respond to Stimuli

• Organisms react in the presence of appropriate stimuli physiologically and behaviorally.

Living Things Reproduce

• All living things come from other living things.

• Living things make copies of themselves; to do so they pass on genes.

Living Things Evolve

• Evolution is change in characteristics of populations/species over time resulting from mutation & natural selection.

• These changes result in adaptations (characteristics that increase the likelihood that species survive and reproduce).