Exercise 1: The Microscope Flashcards
Objects that are smaller than ____________ of a millimeter cannot be seen by the naked eye.
one-tenths
Which type of microscopy uses light to illuminate specimens and creates images where the specimen is dark and set against a bright background?
Light microscopy
Which types of microscopes use a two-lens system to obtain images of thin, minute specimens such as tissue sections and blood smears?
Compound light microscopes
Explain how to properly carry a microscope.
When carrying a microscope, hold it with one hand by the arm and support the base with the other.
How far from the table should a microscope be placed?
A microscope should be placed at least three centimeters from the edge of the table.
Which part of the microscope is the vertical extension of the base?
pillar
Which part of the microscope connects the arm and pillar?
inclination joint
Which part of the microscope controls the movement of the stage clips?
stage control knob
Which parts of the microscope are connected to the eyepiece?
draw tube and body tube
Enumerate the four types of objective lens and their respective magnification.
- low power object (10x)
- high power objective (40x)
- scanning objective (4x)
- oil immersion objective (100x)
Which two knobs control the movement of the stage at smaller and greater intervals?
fine adjustment knob and coarse adjustment knob
Give the two reflecting surfaces of a mirror attached to the pillar of a microscope.
plane and concave
Which part of the microscope focuses light onto the specimen?
condenser
Which part of the microscope regulates the amount of light passing through the aperture?
Iris diaphragm
Which term refers to the condenser and iris diaphragm?
substage
Which solvents can be used to wipe off persistent residue in microscopes?
distilled water, 90-100% ethanol, acetone
Which solvent is recommended when removing thick substances such as immersion oil and hydrophobic stains in microscopes?
Xylene
TRUE or FALSE:
For microscopes with mirrors, set it in a vertical position, facing sideways, before storage.
TRUE
TRUE or FALSE:
For electrical microscopes, set the control for brightness to the lowest level and set the power switch to the off button.
TRUE
TRUE or FALSE:
Set the revolving nosepiece to the lowest possible objective.
TRUE
TRUE or FALSE:
For microscopes with an adjustable body tube, the lowest objective should be at least one centimeter above the stage.
TRUE
TRUE or FALSE:
For microscopes with an adjustable stage, the stage should be set at the lowest level.
TRUE
TRUE or FALSE:
When turning the revolving nosepiece, do not apply pressure on the objective. Place your fingers directly on the nosepiece.
TRUE
TRUE or FALSE:
Use the concave surface of the mirror if the external light source is dim.
TRUE
TRUE or FALSE:
Keep both eyes open when looking through the eyepiece.
TRUE
TRUE or FALSE:
Tilt the microscope only when the specimen is held in place by the stage clips.
TRUE
TRUE or FALSE:
When using LPO, turn the coarse adjustment knob until the objective is about 16 mm above the specimen while looking on one side of the microscope.
TRUE
TRUE or FALSE:
If the adjustment knobs are located on both sides, always turn them simultaneously using both of your hands.
TRUE
TRUE or FALSE:
The object is more or less focused when the HPO is 4 mm above the stage.
TRUE
Which property refers to the ability of the microscope to distinguish two points of an image?
resolution
What refers to the relative size of the final image seen by the eye to the object after light passes through the objective and eyepiece.
linear or total magnification
Which property refers to a number between 0 and 1 that denotes the resolving power of an objective?
numerical aperture
Which property refers to the ratio of the size of a drawing to that of the object drawn?
magnification
Give the formula for magnification
magnification = size of drawing/size of specimen
Which instrument used for measuring microscopic structures possesses a graduated scale with no inherent value?
eyepiece micrometer
Which instrument refers to a slide provided with a scale with known values, usually in tenths and hundredths of a millimeter?
stage micrometer
Give the formula for the calibration constant.
c = [(# of SMD x 0.01 mm/SMD) / (# of EMD)] (1000 μm/mm)
Give the formula for calculating the size of a microscopic object given the number of EMDs spanned by the it’s length.
I = (# of EMD) (c)
