Lab 2 Pre-quiz

Question 1

Binocular tube

Answer 1

Holds 2 eyepieces or oculars

Question 2

Oculars (eyepieces)

Answer 2

2 lenses positioned in binocular tube; magnifies image 10x

Question 3

Diopter adjustment ring

Answer 3

ring at base of left eyepiece; adjusted according to interpupillary distance

Question 4

Stand/arm

Answer 4

used to carry microscope

Question 5

Revolving nosepiece

Answer 5

revolving plate which holds objective lenses

Question 6

Objectives

Answer 6

4 lenses which magnify the image:

1. Scanning objective: magnifies 4x
2. Low power objective: magnifies 10x
3. high power objective: magnifies 40x
4. oil immersion objective (longest objective): magnifies 100x

Question 7

Stage

Answer 7

Platform containing a central opening; contains specimen holder with a spring-loaded finger

Question 8

Mechanical stage

Answer 8

Device which holds the microscope slide in place and moves it along the stage. The control knobs for the mechanical stage are located below the stage and move the slide from side to side and forwards and backwards

Question 9

Condenser

Answer 9

group of lenses below the stage which directs and concentrates the light beam from the lamp to the specimen

Question 10

Diaphragm lever

Answer 10

adjusts the amount of light passing through the condenser; controls brightness

Question 11

Course adjustment knob
•how does it focus the image
•what happens went turned clockwise
•what happens when turned counter clockwise

Answer 11

• Focuses image by raising and lowering the stage
• raises the stage
• lowers the stage

Question 12

Fine adjustment knob

Answer 12

small knob in center of course adjustment knob used for final focusing

Question 13

Base

Answer 13

bottom support; houses lamp

Question 14

Lamp
•what is it
•what kind of bulb

Answer 14

• Light source

* tungsten bulb

Question 15

Voltage control dial or slide

Answer 15

control intensity of light from lamp

Question 16

Power switch

Answer 16

switch on front which turns on lamp

Question 17

Care of the compound microscope

•7 steps

Answer 17

1. Use the microscope assigned to your desk. Obtain the microscope and power cord from the cabinet
2. To carry the microscope, hold the arm with one hand and the base with the other
3. Keep your microscope clean. Use only lens paper to clean the lenses. Do not use paper towels or tissues
4. Never take the microscope apart
5. Do not let the cord hang below the table or become covered with books. It can accidentally be pulled from the table
6. Place the microscope flat on the table at least 4 in. from the edge. Clear everything off the table
7. Report any malfunctions

Question 18

Resolution

Answer 18

ability to distinguish between 2 points that are close together

Question 19

Field of view

Answer 19

The circle of light

Question 20

Depth of field

Answer 20

thickness of a specimen that can be seen in sharp focus at the same time

Question 21

Working distance

Answer 21

Space between the bottom of the objective and the specimen

Question 22

How to prepare a wetmount

•5 steps

Answer 22

1. Obtain a clean microscope slide and cover slip
2. Place a drop of methylene blue in the center of the slide
3. Gently scrape the inside of your cheek with a clean toothpick
4. Mix the cheek cells with the methylene blue on the slide
5. Gently apply the cover slip

Question 23

Compound microscope
•what does it do
•why is it called compound

Answer 23

• It is used to enlarge the image of the specimen

* because it requires 2 lenses for magnification

Question 24

Dissecting microscope
• 3 advantages
• 1 disadvantage

Answer 24

1. larger objects can be viewed (animal organs, fingers)
2. the images are 3D
3. the working distance is large allowing for easy manipulation of the specimen
4. low magnification
5. low resolution

Question 25

Interphase | • 4

Answer 25

* rapid growth * duplication of DNA * DNA in form of chromatin * Basic metabolic processes

Question 26

Prophase | •6

Answer 26

* Chromatin thicken and shorten to form chromosomes * Chromosomes are composed of 2 chromatids joined at the centromere * nuclear membrane disappears * nucleolus disappears * Centrioles move to opposite poles * spindle fibers form

Question 27

Metaphase

Answer 27

Chromosomes line up along equator

Question 28

Anaphase

Answer 28

Chromatids separate at centromere and are pulled to opposite pole by spindle fibers

Question 29

Telophase | •5

Answer 29

* Chromosomes movements stop * Chromosomes uncoil to form chromatin * Nuclear membrane reforms * Nucleolus reappears * Spindle fibers disappear