Chapter 3 LAB
Resolution
Ability to discriminate 2 close objects
Objective lenses
Adjustable lens system
Iris diaphragm lever
Arm attatched to the base of the condenser that regulates the amount of light passing through the condenser
Delivers a concentrated beam of light to the specimen
Condenser
Does the depth of field increase or decrease at higher magnification?
Decrease
Does the working distance increase or decrease at higher magnification?
Decrease
Ocular
Eyepiece
The area of the specimen seen when looking through the microscope is the
Field
Used for precise focusing once initial focusing has been done
Fine adjustment knob
Virtual image
Image is erect and appears to be where it is not
Does the amount of light needed increase or decrease at higher magnification?
Increase
Does the resolution increase or decrease at higher magnification?
Increase
Used to increase the amount of light passing through the specimen
Iris diaphragm
Why should the light be dimmed when looking at living (nearly transparent) cells?
It increases the contrast
Only half of the field is illuminated
Lens is not correctly rotated into place
Substage light or mirror
Located in the base. Light passes directly upward through the microscope
Secures the slide to the stage
Mechanical stage or spring clips
Carries the objective lenses; rotates so that the different objective lenses can be brought into position over the specimen
Movable nosepiece
If, after focusing in low power, only the fine adjustment need to be used to focus the specimen at the higher powers, the microscope is said to be
Parfocal
Stage
Platform the slide rests on while being viewed
Nosepiece
Rotating mechanism at the base of the head Carries three or four objective lenses
Field does not change as mechanical stage is moved
Slide is not correctly positioned in the clamp
Condenser
Small substage lens that concentrates the light on the specimen
Proper procedure for preparing a wet mount
Specimen on slide with medicine dropper Mix with toothpick Add stain and mix Cover with coverslip
Platform on which the slide rests for viewing
Stage
Base
Supports the microscope
Head or body tube
Supports the objective lens system
Working distance
The distance from the bottom of the objective lens in use to the specimen is called the
Assume there is an object on the left side of the field that you want to bring to the center (that is, toward the apparent right). In what direction would you move your slide?
To the left
Fine adjustment knob
Used for precise focusing once coarse focusing has been completed
Coarse adjustment knob
Used to focus on the specimen
Arm
Vertical portion connecting the base and head
