Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
66 Cards in this Set
- Front
- Back
|
what is the numerical aperture for the 10x objective lens?
|
0.25
|
|
|
what is the numerical aperture for the 40x objective lens?
|
0.65
|
|
|
what is the numerical aperture for the 100x objective lens?
|
1.25
|
|
|
what is the formula for calculating magnification?
|
magnification = ocular x objective
|
|
|
calculate the total magnification when using the oil immersion lens (100x)
|
10 x 100 = 1000x magnification
|
|
|
what is the formula for calculating resolution?
|
R = (wavelength)/2NA
NA= numerical aperture |
|
|
calculate the resolution of 10x magnification with an illumination of 550nm
|
R=550nm/2(0.25)
R=1100nm |
|
|
calculate the resolution of 40x magnification with an illumination of 550 nm
|
R=550nm/2(0.65)
R=423nm |
|
|
calculate the resolution of 100x magnification with an illumination of 550 nm
|
R=550nm/2(1.25)
R=220nm |
|
|
calculate the resolution of 10x magnification with an illumination of 450nm
|
R=450nm/2(0.25)
R=900nm |
|
|
calculate the resolution of 40x magnification with an illuminaiton of 450 nm
|
R=450nm/2(0.65)
R=346nm |
|
|
calculate the resolution of 100x magnification with an illuminaiton of 450nm
|
R=450nm/2(1.25)
R=180nm |
|
|
which wavelength, 450nm or 550 nm, would allow you to view objects that are closer together? explain your reasoning.
|
the wavelength of 450nm would allow you to view objects that are closer together. This is because the resolution values are smaller. When the resolution values are smaller it allows you to view objects that are that far apart and anything that may be farther apart.
|
|
|
STUDY THE COMPONENTS OF A MICROSCOPE AND BE ABLE TO IDENTIFY EACH ONE
|
!!!!!!!!!
|
|
|
what are the proper steps in putting away and handling a microscope?
|
you should use both hands when carrying the microscope. one hand should be on the arm and the other on the base of the microscope.
|
|
|
why is it necessary to use immersion oil when using the 100x objective lens?
|
the 100x lens only works properly when it is immersed in oil. the immersion oil has the same refractive index as the glass slide so when you use it not as much light is lost to refraction.
|
|
|
who published his discovery of "cells" in cork in 1665?
|
Robert Hooke.
|
|
|
Who observed bacteria and protozoa using a homeade microscope?
|
Antony Van Leeuwenhoek.
|
|
|
what is a TEM? how does it work and what components of a cell can you see with it?
|
operates similiar to the compound microscope except that it uses electrons rather than light. the electrons give a much higher resolution. the electrons are emitted thru the column of the microscope and are then focused into a thin beam by electromagnetic lenses. this beam goes thru the specimen. the electrons hit a flourescent screen and produce the image that you see. it allows you to view the internal structures of bacteria and viruses.
|
|
|
what is the SEM? how does it work and what components of a call can you see with it?
|
in a scanning electron microscope a stream of elctrons pass thru two condenser lenses which form a thin beam of electrons. a set of coils scan the beam and the final lens focuses the beam onto a part of the specimen. it continues to scan various parts of the specimen until a final image is produced. the SEM allows you to view the surface of a cell and its shape and size.
|
|
|
list the steps for preparing a wet mount
|
obtain a clean glass slide
place a drop of water in the center of the slide add a small amount of yogurt/specimen to drop of water place cover slip gently on top observe specimen(s) using all 3 objective lenses |
|
|
what units are used to measure bacteria and other microorganisms?
|
micrometers
|
|
|
what units are used to measure viruses?
|
nanometers
|
|
|
what are some examples of things you can see with the compound microscope?
|
hair follicle
cell bacterium |
|
|
what are some examples of things you can see with the electron microscope?
|
virus
atom small molecules macro molecules |
|
|
what are some functions of a compound microscope?
|
enlarge cells for viewing
have 2 sets of magnifying lenses utilize light for viewing most commonly used scopes |
|
|
what are the 2 types of magnifying lenses for a compound microscope?
|
ocular-located in the eyepiece, has a magnification of 10x
objective-most scopes have 3 10x-low power 40x-high power or high dry 100x-oil immersion |
|
|
what is the function of the stage of the compound microscope?
|
flat table-like area on which to place slides/samples to be viewed
|
|
|
what is the function of the stage clips of the compound microscope?
|
holds the slide in place
|
|
|
what is the funciton of the stage adjustment knobs of the compound microscope?
|
allow for front to back and side to side movement of the slide
|
|
|
what is the function of the illuminator of the compound microscope?
|
it is the light source for the microscope
|
|
|
what is the funciton of the condenser of hte compound microscope?
|
focuses the light from the illuminator onto the specimen slide
|
|
|
what is the funtion of the iris diaphragm of the compound microscope?
|
controls the amount of light that enters the condenser
|
|
|
VIEW THE PATH OF LIGHT IN A LIGHT COMPOUND MICROSCOPE
|
!!!!!!!!!
|
|
|
what is magnification?
|
the product of the power of the ocular lens times the power of the objective lens that is in use
|
|
|
immersion oil bridges the gap between the ____ and the _____ which decreases the amount of light lost to _____.
|
glass, objective lens, refraction
|
|
|
why is the light from main source of the compound microscope refracted?
|
light bends as it passes from one medium to another and the difference in relative refractive indices.
|
|
|
true or false: refraction increases the ability to see the image
|
false. it decreases the ability to see the image. enough light passes thru with the 10x and 40x
|
|
|
what is the refractive index of air and glass?
|
air-1.00
glass-1.56 |
|
|
why is immersion oil useful in using the 100x lens?
|
it has the same refractive index as glass.
|
|
|
what is numerical aperture?
|
a mathematical way of describing the light gathering ability of a lens system, and depends on 2 factors
|
|
|
what are the 2 factors that numerical aperture depend upon?
|
the size of the cone of light the lens can recieve
the medium the light must pass thru b/n the lens and the specimen numerical aperture is usually stamped on each objective lens |
|
|
what is resolution?
|
the ability of a lens to distinguish b/n 2 objects at a specified distance apart
2 objects can only be seen if they are far apart enough for light to pass b/n them |
|
|
resolution is not magnification; which is a scope's ability to increase _____ not _____.
|
size, clarity
|
|
|
what is the microscopic field?
|
the area of the microscope slide that you see through a lens
field decreases as higher power objectives are used |
|
|
VIEW PICTURES OF THYROID FOLLICLES AND SIMPLE CUBOIDAL EPITHELIUM WITH EACH OBJECTIVE LENS
|
!!!!!!!!!
|
|
|
true or false: parfocal lens stay in place when magnification/focal length is changed
|
true
|
|
|
true or false: images are all on the same focal plane for all objectives
|
true
|
|
|
how does parfocal aid in viewing specimens under the microscope?
|
prevents the necessity for large focus adjustments when switching objectives for viewing a specimen. small adjustments of focus with fine adjustment knobs will probably be required
|
|
|
true or false: when switching to a different objective lens the object does not remain in focus
|
false. only minimal adjustments with the fine focus is needed
|
|
|
what should you use to clean lenses?
|
lens paper only
|
|
|
what should not be used to clean lenses?
|
paper towels
kimwipes etc. they will scratch the lenses |
|
|
what are some other methods of care of the microscope?
|
keep cords tucked up and out of the way to prevent tripping and scope falling off table
dont remove any parts of scope, if a part falls off notify your instructor take care when using the course adjustment knob so that you dont raise the stage too hight and crack the slide or damage a lens |
|
|
what is the first step in focusing the specimen image?
|
turn light on and adjust the light up halfway. light can be adjusted by on/off dimmer switch and the iris diaphragm lever.
|
|
|
what can you use to acheive maximum working distance?
|
coarse adjustment knob
|
|
|
what is working distance?
|
the distance b/n the objective lens in use and the slide on the stage
|
|
|
what step follows turning on light and using coarse adjustment knob?`=
|
making sure that the iris diaphragm is wide open
|
|
|
what step follows ensuring that the iris diaphragm is wide open?
|
obtain a slide and clip it into place on the stage
|
|
|
list the steps of focusing
|
obtain a slide and clip in into place on the stage
use stage adjustment knob to position the specimen over the hole in the stage make sure the low power (10x) lens is in place use coarse adjustment knob to raise the stage and get minimum working distance-watch from the side as you raise the stage once specimen is in focus with 10x lens you can switch to 40x lens rotate 40x lens into position using the nosepiece once in focus rotate the nosepiece halfway b/n the 40x and the 100x lens place a drop of oil on the slide rotate 100x lens into place |
|
|
true or false: it is ok to rotate the 10x and 40x lens through the immersion oil
|
false
|
|
|
true or false: you should only use the fine adjustment knob to sharpen the focus when using the 100x lens?
|
true
|
|
|
true or false: it is never necessary to increase the amount of light being let into the lens when using the 100x lens?
|
false. you can increase the amount of light by using the iris diaphragm lever or the light adjustment knob
|
|
|
describe after use care of the microscope
|
turn off scope
remove slide lower stage clean lens with lens paper rotate nosepiece so that the 10x lens is in place center stage wrap cord around base cover scope an return to where it was stored |
|
|
true or fasle: professionally prepared slides should be thrown in biohazard container when done using them
|
false. only slides that you yourself prepared are required to be thrown in the biohazard container when done using.
|
|
|
true or false: plastic pipets should go in the "sharps" container
|
true
|
|
|
REVIEW QUIZ AND ANY EXTRA STUFF POSTED ON BLACKBOARD IN FOLDER
|
!!!!!!!
|
