B1 Flashcards
How do you calculate the magnification of the light microscope you are using?
Magnification of the eyepiece lens x magnification of the objective lens
What does magnification equal?
Size of image/size of real object
What is resolution? What is resolution power?
The ability to distinguish between two seperate points. Resolution power of a micrsocope is what affects how much detail it can show.
What are the resolving powers of each microscope?
Light - 200nm
Scanning electron - 10nm
Transmission electron - 0.2nm
Compare light microscopes and electron microscopes.
Light microscopes:
Easy to use
Relatively cheap
They use light resolution is limited
Electron microscopes:
Very expensive
Hard to use
Use electrons
Can use them to study sub-cellular structures because of their resolution
What is the job of the nucleus?
Controls the activities of the cell. Contains the genes on the chromosomes that make proteins to build new cells.
What is the job of the cytoplasm?
Where most of the chemical reactions needed for life to take place.
What is the job of the cell membrane?
It controls what goes in and out of the cell.
What is the job of mitochondria?
Where aerobic respiration takes place, releasing energy for the cell.
What is the job of the ribosomes?
Where protein synethesis takes place, making all the proteins needed in the cell.
What is a cell wall?
Made of cellulose that strengthens the cell and gives it support.
What are chloroplasts?
Where photosynthesis takes place so the plant has food.
What is a permanent vacuole?
Full of cell sap. Important for keeping the cells rigid to support the cell.
How are plant cells different to animal cells?
They make their own food by photosynthesis. They do not move their whole bodies about from one place to another. Plant cells are often rather bigger than animal cells
What is a eukaryotic cell?
They have a cell membrane, cytoplasm and genetic material that is enclosed in a nucleus. Animal and plant cells.
What are prokaryotic cells?
prokaryotic cells from prokaryotic organisms have a cytoplasm surrounded by a cell membrane, and a cell wall that does not contain cellulose. The genetic material is a DNA loop that is free in the cytoplasm and not enclosed by a nucleus.
Sometimes there are one or more small rings of DNA called plasmids
What do plasmids do?
They code for a very specific feature
What do flagellum do?
flagellum (plural: flagella), that is, a long protein strand that lashes about. These bacteria use their flagella to move themselves around.
How are nerve cells adapted?
There function is to carry electrical signals around the body.
They are long (to cover more distance)
Branched connections at their ends to connect to other nerve cells and form a network throughout the body.
How are muscle cells adapted?
The function is to contract quickly.
They are long (so they have space to contract)
Contain lots of mitochondria to generate the energy needed to contract
How are sperm cells adapted?
The function of the sperm cell is to get the male DNA to the female DNA.
It has a long tail and a streamlined head to help it swim to the egg
Lots of mitochondria to provide energy
Enzymes in the head to digest through the egg cell membrane
