Cells Flashcards
What are the advantages of using a light microscope over an electron microscope?
- living cells can be observed
- natural colour can be seen
- movement can be observed
What are the disadvantages of using a light microscope instead of an electron microscope?
Limited magnification
Limited resolution
What are the advantages of using a scanning electron microscope instead of other microscopes?
High magnification x500,000
High resolution (20nm)
3D image
What are the disadvantages of using a scanning electron microscope over other microscopes?
High energy electrons can destroy specimen. Preparation distorts specimen Vacuum required so none living cells Images are black and white Cells are dehydrated
What’s 2 advantages of using a transmission microscope over others?
High magnification x500,000 High resolution (0.1nm) (shorter wavelength)
What are the disadvantages of using a transmission electron microscope over others?
Very thin preparations required High energy electrons can destroy the specimen Preparation distorts the specimen Vacuum required Black and white Cell is dehydrated
What samples require iodine as a stain when being viewed under a microscope?
Onion membrane
Potato
How do electrons microscope work?
The electrons (e-) are focused using electromagnets.
What do eukaryotic cells have that prokaryotic cells don’t?
Membrane bound organelles
Nucleus
Larger ribosomes
What do prokaryotic cells have that eukaryotic cells don’t have?
Nuceoid Smaller ribosomes Plasmids Cell wall of murine Capsule 1+ flagella
What 2 features of viruses make them unique?
Acellular
Non-living
What features do viruses contain?
Capsid
DNA/RNA
Proteins
How calculation do you use to work out the size of an object when view biological structures under a microscope?
Size of the object=size of the image/magnification
Why might there be more Golgi or mitochondria in mucus secreting cells?
More energy is required (mitochondria) and more enzymes and proteins are required in the mucus (Golgi)
Name two features of mitochondria.
Cristae
Matrix
