Cell Theory

Anton van Leeuwenhoek  1674 Holland (isn’t that weird…)  First compound light microscope  First to see bacteria, called them “animacules”  Studied pond water, blood, tooth scrapings

Robert Hooke  1655 England  Coined the term “cell” to describe the chambers in cork  Cell walls look like little rooms in the monastery

Matthias Schlieden  1837 Germany  All plants are made of cells

Theodor Schwann  1837 Germany  All animals are made of cells  Once, while talking at dinner with his friend, Matthias Schleiden, Schwann compared the parts of plants and animal cells, and they realized that they had similar parts!

Rudolf Virchow  1837 Germany  First to see leukemia cells  Has an autopsy method named after him  Cells can only arise from pre-existing cells pre-existing cells

Francesco Redi  1668 Italy  Disproved the theory of spontaneous generation

Francesco Redi’s Experiment

Louis Pasteur  1862 France  Disproved the theory of spontaneous generation  Developed the process of pasteurization

Pasteur’s Experiment

From the work of these and many other scientists, we have the Cell Theory

Cell Theory 1. All living things are made up of at least one cell. 2. The cell is the basic unit of structure and function in living things. 3. Cells come only from other living cells.

How did the microscope change human understanding of life?  Why were cells not discovered before the microscope was invented?  Many diseases, such as strep throat, are caused by microscopic organisms. Why might a microscope be an important tool for a doctor?  Who’s work was the most important in the formation of the cell theory? Justify your answer with details from your notes and/or video.

Levels of Organization in Multicellular Organisms Organelles  Cells  Tissues  Organs  Organ Systems  Organism* * An organism can be unicellular

Grade 8 Review On loose leaf to hand in for a classwork grade tomorrow Test TOMORROW: In the Earth’s Surface Book: Complete questions on pg , 20 and 22 on pg on pg on pg 107 5, 6, 10, 15 and 16 on pg on pg 173

If students finish early: Start reading section 4.2 and take 2 column notes. Fold notebook page in half:  Soil  Four materials that make up soil  Organic material  Mixture of weathered rock particles and other materials  Weathered rock, organic material, water and air  Remains and waste products of plants and animals as well as HUMUS (decaying material)

 Kind of soil depends on many factors  Soil horizons (A, B and C)  Kind of rock, climate, landforms, plant cover, animals and other organisms  A – upper layer (topsoil) most organic material, often dark colored because of all the humus  B – little organic material, brownish- reddish, clay and minerals

 Soil horizons (A, B and C)  Soil properties  C – deepest layer, largest and least weathered rock particles, light yellowish-brown in color  Texture, color, pore space, chemistry