Lab quiz 1 Flashcards
what are the three general rules of the microscope
-do not remove any parts of microscope
-clean lends daily with provided paper
-do not touch the glass surface with fingers
how do you calculate the actual size of cell or microscopic organism
diameter os feild of veiw of selected object/# of times the cell or organism can fit across the field of view
what structures do all living things have in them
plasma membrane, cytoplasm, DNA and ribosomes
what are light micro scopes good for
looking at fresh material or prepared slides.
whole or parts of living organisms are often observed using conventional light micospoes
what are some weaknesses of the light microscope
some organisms are transparents and have little contrast. stains of special light microscopes with different optical arrangements could fix this
how does florescent microscopes work
they absorb one particular wave length and emit some of that absorbed light at another wavelength
what are some naturally occurring florescent molecules
chlorophyll and lignin in plant cells
what are florecent dyes or antibodydye complexes used for
to lable spicific molecules e.g. proteins, DNA, or organells within the cell
in florescent microscopy how are the florescence displayed
on a black background
how does confocal laser scanning microscopy work
it involves focusing a laser light source onto a very thin plane within a naturally fluorescent specimen or one treated with comercial florescent dyes
laser scanned scaned speciman emit flouorecence that is detected in digital form and a thin, detailed optical section is constructed by the microscopes computer
what is confocal laser scanning good for
it is used to examine specimans that are too thick to be examined with fluorescence mirosopy
what kind of microscopy can be constructed into a 3D image
confocal laser scanning microscopy
what are some light microscopes
fluorescence microscopy
confocal laser scanning microscopy
how do electron microscopes work
they work similarly to light microscopes, except the image is produced by a beam of high velocity electrons instead of a beam of light
what is electron microscopy good for
they are good for looking at very small objects, such as the internal structure of a cell
what has greater resolution power? light or electron microscopes
electron
how much smaller times things can electron see compared to light microscopes
things about 500x smaller then the light microscope can see
what are the two types of electron microscopes
transmition electron microscopes (TEM)
scanning electron microscopes (SEM)
how does the scanning electron microscopy work
a beam of electrons is scanned over the surface of a speciman resulting in a detailed three-dimentinol image of the surface of a speciman
what is scanning electron microscopy used for
it is used for intact specimens such as insects and pollen grains
how does a transmission electron microscopy work
a beam of electrons is transmitted through an extremely thin section of specimen
simular to how light passes a slide in conventional light microscopy
what are prokaryotes
they are often unicellular but some geners may form chains or agggregates
what are chains and aggregates called
chains are called filaments and aggregates are called colonies
what is the central area of a prokaryote called and what does it contain in it
its called the nucleoid which contains genes
no prokaryotes have organells and nucleous
no
in addition to there plasma membrane most bacterial cells have…
cell walls
what is the cell walls of bacteria composed of
polysaccarides and amino acids
what do many bacterial cells secrete
a gelationous outer covering called glycoalyx
what does glycoalyx do
it traps water and protects the bacterium from desiccation
bacterial cells have very thick glyocalyx called
capsule
what is does the capsule of some bacteria do
prevents the bacteria from being destroyed by an animals immune system when ingested or inhailed. or it may help they bacteria to stick to surfaces
what is under the capsule of bacteria
the cell wall and plasma membrane
what is the material within the cell of a bacteria
the cytoplasm which contains the ribosomes
what are ribosomes
the structures that synthesize proteins
what is the nucleoid in bacteria
it contains the single circular chromosome
what is plasmids in bacteria
other circular prices of DNA
what do eukaryotes range from
they range from unicellular (single cell protist) to multicellular organisms (e.g. fungi, plants, and animals). colonial organisms are the intermediate
what are colonial
they may be composed of a group of structrally and functionally simular cells that adhere toeachother and may comunicate with eachother
what do eukaryotes have the prokaryotes do not
they have a membrane bound nucleus and membrane bound organelles
what is the view diameter of the 4x, 10x, and 40x
the 4x is 4.40mm
the 10x is 1.75mm
the 40x is .44mm
on a microscope where should the iris diaphragm adjustment lever be. what does this open
to the left to fully open the diaphram
how do you adjust the condencer
by holding a pencil over the light source and lowering the condenser assembly (using the condenser adjustment knob on the left) until you have a very sharp shadow
how do you maximize resolution of the microscope
the iris diaphram adjustment lever should be moved to the right to the point of some loss of light can be detected in the field of view. do this every time you swith objective lenses
