the discovery of the cell cell: the smallest unit that can carry on all the processes of life....
TRANSCRIPT
The Discovery of the CellCell: the smallest unit that can carry
on all the processes of life.
Because the cell is SO small, we need microscopes to see them.
The Discovery of the Cell
Robert Hooke 1665: EnglishLooked at the corkNamed the small components within the cork
“cells” because they looked like the cell blocks from prison.
He was looking at the cell walls of dead plants.
***Yes, cork comes from a plant!
The Discovery of the CellAnton Van Leeuwenhoek (pronounced “Levin-
hook”) 1700-DutchFirst person to actually observe a living cell!Improved lenses of the microscopesObserved pond water and scrapings of teeth!
The Discovery of the Cell
Matthias Schleiden and Theodore Schwann (German)Schleiden- observed plants and said “all plants are
made of cells”Schwann- observed animals and said “all animals
are made of cells”These two side theories led to part of the cell theory
The Cell Theory1. All living things are made of cells.
2. Cells are the basic structure and function of living things.
3. All cells come from pre-existing cells.
MicroscopesLight Microscope
Light passes through the object or lense to eye or
computer
Magnifies up to 1000x
Bacterium or larger (0.2 micrometers in diameter)
Cannot see the internal cell structure
Useful for living specimen
Electron Microscope
Uses beams of electrons that bounce of
objects to create image
Magnifies up to 1,000,000 x
Reveals details of internal cell structure
Specimen must be dead
SEM: Scanning Electron Microscope
studies the surface structures of objects/cells
TEM: Transmission Electron Microscope
Explores deep internal structures of
objects/cells
Micrograph: photograph taken through
an electron microscope.
Cell StructureOrganelles: internal structures of the cell
Each organelle has a specific function.
Plant and animal cells DO NOT have all the same organelles.
Cell Shape Example:
Cells of the nervous system need to carry information from your brain all the way to your toes.
Therefore, they are long and skinny.
Cell Shape Example:
Blood cells need to travel smoothly through veins and vessels.
Therefore, they are small and round.
2 main classes of CellsProkaryotic Eukaryotic
Lacks a nucleus, but still has most organelles.
Has a nucleus, and has organelles.
DNA is not separate from the cell.
DNA is protected inside the nucleus.
Size: 1 - 10 micrometers Size: 10 – 100 micrometers
Example: Bacterial Cell Example: Plant or Animal Cell
Cell Organization in Multicellular Organisms
CellsThe smallest unit of life capable of carrying out all
functions/characteristic of life.Tissues
A group of cells working together towards the same function.
OrgansSeveral types of tissues functioning together for a
specific purpose.Organ System
Several organs working together to perform a function to help the organism carry out all other functions.
OrganismAll the organ systems working together to create one
being.
Tissues of Plants
Dermal TissueForms the outer layer of the plant
Ground TissueMakes up the bulk of the roots and stems
Vascular TissueTransports water and food throughout the
plant