Hairy T-cell
Theory Definition: An idea that has been proposed, repeatedly tested, and found to be true-so far. A scientific hypothesis that survives experimental testing becomes a scientific theory
Cells The basic units of a living system or organism
Unicellular Further explaining the CELL THEORY PART 1 multicellular Multicellular unicellular Multicellular Unicellular
If an organism is unicellular (made of only ONE cell), such as a paramecium, is it considered living? YES, according to the first part of the cell theory: All living things are composed of cells, If an organism has cells, even if it only has 1 cell, it is a living (biotic) organism.
Unicellular organisms Some organisms only consist of a single cell But these do usually have the components of cells (nucleus, membrane etc) Image Credit Paramecium
2 Types of Cells: Prokaryotic - Cells that don t have a membrane-covered nucleus for example: bacteria Eukaryotic Cells with a nucleus covered by a membrane for example: plant and animal cells
Prokaryote Eukaryote
If an organism is prokaryotic, is it considered living? YES, even though prokaryotic CELLS do not have a nucleus, it is still a living thing because it is a type of CELL.
READ ONLY: Form Fits Function Cell have different shapes (structure) to enable them to perform different tasks (function)
How do we know cells exist? Invention of the microscope made it possible for people to discover and learn about cells Robert Hooke looked at cork cells Anton van Leuenhock used a simple microscope and was the first person to see microorganisms.
Not ALL cells are microscopic Ostrich eggs are the largest unicelluar organism
Who was Robert Hooke? (1665) - used a compound microscope to look at cork (from bark of a tree) & he saw empty boxlike structures that he named cells.
What he saw?
Who was Antonie van Leewenhooke? (mid 1600 s) - used a simple microscope to look at pond water. - was the first to observe microorganisms in pond water.
Anton van Leeuwenhoek First compound light microscope
What did van Leeuwenhoek s microscope look like?
Cell Theory developed by 3 German scientists: Matthias Schleiden, Theodor Schwann, and Rudolf Virchow
Definition = Three part theory about cells 1. All living things are made of cells.
Part 2 of the Theory 2. The cell is the building block and basic unit of life.
Who came up with this theory? 1. Schleiden (circa 1838) All plants are made of cells! Onion skin cells
Who was Matthias Schleiden? (1830 s) Onion cells Elodea cells Cork cells - studied numerous plant parts under the microscope and declared ALL PLANTS ARE MADE OF CELLS!
Who came up with this theory? 2. Schwann All animals are made of cells! Human red blood cells
Who was Theodor Scwhann? (mid 1830 s) - Cheek cells Amphibian Blood - Used a microscope to observe numerous animal tissues and declared ALL ANIMALS ARE MADE OF CELLS!
Part 3 of the Theory 3. All cells come from pre-existing cells. yeast cells dividing
Who came up with this theory? 3. Virchow All cells come from pre-existing cells!
Who was Rudolf Virchow? (Mid 1830 s) - observed living cells dividing and declared ALL CELLS COME FROM OTHER LIVING CELLS!
These scientists discoveries led to the cell theory What is the CELL THEORY??? Theory that states 1. All organisms are made of one or more cells. 2. The cell is the basic unit of life which can perform life processes. 3. All cells come from other living cells.
READ ONLY REVIEW Cell Theory: 1. All living things are made of CELLS. 2. The CELL is the basic structural and functional unit of life. 3. All CELLS come from preexisting cells.
Some Random Cell Facts The average human being is composed of around 100 Trillion individual cells!!! It would take as many as 50 cells to cover the area of a dot on the letter i WOW!!!
Organelles -Tiny cell structures that are specialized parts of a cell that have specific functions a cell organ.
If Cells could be really big Star Trek - The Immunity Syndrome