The Characteristics of Cells Living Things Are Made of Cells Organisms- any living thing Ex. Bacteria A living thing is composed of cells or was once composed of cells. Ex, mushroom or dead tree limb A nonliving thing was never alive and never had cells. Cells – the smallest unit of a living thing. Smallest living thing

Cells are the Building Blocks of Life Unicellular- organism composed of one cell. Example Bacteria, amoeba Multicellular- organisms composed of more than one cell Example: All animals and most plants are multicellular

The Cell Theory New cells are only produced from other living cells Cells Come From Existing Cells New cells are only produced from other living cells Cells reproduce To create new cells so that the organism can grow and carry out life processes To replace old, weak, dead cells To continue the survival of unicellular species

The Cell Theory All living things are made of one or more cells Cells are the smallest unit of living things All cells come from preexisting cells through cell division

Robert Hooke How Did He Discover/Name Cells While looking at a thin slice of cork under the microscope, he saw small compartments that reminded him of a monk’s room in a monastery called a “cell.” Why Was His Discovery Important His findings led to the scientific study of the cell (cell biology) and the creation of the cell theory Who Was He? Born in England1635/Died 1703 Was an architect, naturalist and scientist Worked with cells and physics What Did He Do? Built a compound Microscope Used it to examine organisms such as insects

Scientist Contributions to the Cell Theory 1662-1723 Anton van Leeuwenhoek Created his own microscope Was the first microbiologist. Discovered single celled organisms he called animalcules. Today they are known as bacteria. 1838 Matthias Schleiden concluded all plants are made of cells 1839 Theodor Schwann concluded all animals are made of cells 1855 Rudolf Virchow proposed cells are formed from only from cells that already exist. All cells come from cells

Parts of the Microscope 1. allows user to change objective lenses 2. lenses that rotate on the microscope, each of which has a different magnification 3. holds the microscope slide in place 4. place to put the slide 5. regulates the amount of light that hits the slide 6. light source 7. the eyepiece or first lens the user looks through 8. keeps the two sets of lenses the correct distance apart 9. place where user holds microscope 10. moves the stage up and down to bring specimen into focus 11. moves objective to make the image sharper 12. holds up the microscope

Microscope Parts 1. Rotating Nosepiece 2. Objective Lens 3. Stage Clips 4. Stage 5. Diaphragm 6. Light Source 7. Ocular Lens 8. Body Tube 9. Arm 10. Coarse Adjustment Knob 11. Fine Adjustment Knob 12. BAse This Photo by Unknown Author is licensed under CC BY-SA