Robert Hooke’s contribution the the cell theory.
Robert Hooke observed cork under a microscope and saw box-like structures. He named them cells.
Anton Van Leeuwenhoek’s contribution the the cell theory.
Anton Van Leeuwenhoek observed his own blood and sperm, as well as pond water.
Robert Brown’s contribution the the cell theory.
Robert Brown observed the nucleus. He believed all cells had one.
Matthias Schleiden’s contribution the the cell theory.
Matthias Schleiden proposed that all plants were made of cells.
Theodor Schwann’s contribution the the cell theory.
Theodor Schwann proposed that all animals were made of cells, then that all living things were.
Rudolph Virchow’s contribution the the cell theory.
He gathered enough info to develop a proper cell theory.
List four points of the cell theory.
- All living things are composed of one or more cells.
- Cells are the basic unit of structure and function in all organisms.
- All cells arise from previously existing cells.
- The activity of an entire organism depends on the total activity of individual cells.
How are prokaryotic cells more primitive than eukaryotic cells? (3)
- Smaller
- No organelles
- No nucleus (DNA is in a single chromosome)
Describe the nucleus. (6)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Eukaryotic only
- Usually the largest organelle
- Contains the cell’s DNA
- Contains instructions for making a cell work
- Contains one or more nucleolus (pl. nucleoli)
- Surrounded by a double-layered nuclear membrane
What do the nucleoli within a nucleus do? (1)
- Produce ribosomes which assemble protein
What are three reasons why cells have a limit to how big they can grow?
- As cells get bigger, they need more stuff and produce more waste.
- Cell membranes are weak and will eventually burst.
- Cells need to send messages within themselves. Eventually, messaging will not be efficient.
Define / describe the cell membrane. (2)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Eukaryotic and Prokaryotic cells.
- Encloses the entire cell and regulates what goes in and out.
Define / describe the cytosol. (2)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Eukaryotic and Prokaryotic cells.
- Jelly-like material between cell membrane and nuclear membrane.
- Contains necessary materials for cell function.
Describe the cytoplasm. (1)
* What cell is it found in?
* what does it look like?
* What is its purpose?
Cytoplasm includes the cytosol and all organelles within.
Define / describe the mitochondria. (5)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Eukaryotic only.
- Roundish organelles surrounded by two membranes with the inner one being folded.
- Produces energy for the cell and entire organism
- Mitochondria have their own DNA and can replicate themselves
- Were once independent bacteria
Define / describe the endoplasmic reticulum. (2)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Network of membrane enclosed, fluid filled tunnels that form a continuous network through the cell.
- Provides transportation paths through the cell.
What is the difference between rough and smooth endoplasmic reticulum? (3)
- Smooth endoplasmic reticulum produce fat
- Rough endoplasmic reticulum produce protein
- Rough endoplasmic reticulum have ribosomes on the surface
Define / describe the golgi body. (4)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Eukaryotic only
- Stacks of flattened membrane sacs
- Processing, packaging, and storing centres for cell products
- Works closely with the E.R.
Define / describe vacuoles. (4)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Eukaryotic and prokaryotic
- Fluid filled membrane bubbles
- Store food, water, waste, etc.
- Tend to be larger in plants
Define / describe the cell wall. (5)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Eukaryotic and prokaryotic
- Not in animal cells
- Thick, rigid walls outside of cell membranes
- Supports cell and entire plant
- Consists of different material for different organisms (For plants, it is cellulose)
Define / describe lysosomes. (4)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Eukaryotic only
- Small vacuole-like structures
- Contains powerful digestive enzymes
- Breaks down things (large food bits, worn-out organelles, or unwanted visitors like bacteria)
Define / describe chloroplasts. (6)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Eukaryotic only
- Only in plants and algae (photosynthic protists)
- Surrounded by two membranes
- Contains chlorophyll (pigment that makes plants green)
- Where photosynthesis takes
- Similar to mitochondria, it clones itself
What is photosynthesis? (2)
- A process used by plans to make their own food
- Carbon dioxide + ENERGY = SUGAR
Define / describe centrioles. (4)
* What cell is it found in?
* what does it look like?
* What is its purpose?
- Eukaryotic only
- Only animal cells and similar protists
- Paired cylindrical structures
- Function in cell division
