Microscope 🔬

Question 1

Body Tube

Answer 1

•Separated the eye piece from the objectives

Question 2

Revolving Nosepiece

Answer 2

• Holds the objectives and allows the objectives to rotate

* Holds objective lens

Question 3

Scanning Objective Lens

Answer 3

• Very low power

* Magnifies about 4x

Question 4

Low Power Objective Lens

Answer 4

• Magnifies about 10x

* Locates the specimen

Question 5

High Power Objective

Answer 5

•Magnifies about 40x

Question 6

Light Source/ Illuminator

Answer 6

•Provides light so specimen could be seen (some have mirrors)

Question 7

Diaphragm

Answer 7

• Controls the amount of light passing through the opening of the stage
• Can be adjusted

Question 8

Coarse Adjustment

Answer 8

• Used for focusing with the low power objective only
• IT MUST NEVER BE USED WITH THE HIGH POWER OBJECTIVE
• Used for first focusing

Question 9

Fine Adjustment Knob

Answer 9

• Used for for focusing with the high power or the low power objective
• It should never be turned more than 1/2 turn in either direction
• Used for final adjustment

Question 10

Arm

Answer 10

•Supports the body tube and is used for carrying the microscope

Question 11

Stage

Answer 11

•Supports the slide being used

Question 12

Stage Clips

Answer 12

•Holds the slide in place

Question 13

Base

Answer 13

•Supports the microscope

Question 14

Inclination Joint

Answer 14

•Can be used to tilt the microscope

Question 15

Eye Piece

Answer 15

• Ocular Lens

* Contains a lens that magnifies about 10x

Question 16

Microscope

Answer 16

•An instrument that makes small objects look larger

Question 17

Simple microscope

Answer 17

•Has one lens (a hand lens)

Question 18

Compound microscope

Answer 18

•Has more than one lens (at least 2)

Question 19

Robert Hooke

Answer 19

• 1663
• Improved compound microscope by adding light
• First to see “cells” (from cork)
• First to use the term “cells”

Question 20

Anton van Leeuwenhoek

Answer 20

• 1683

* First to see unicellular organisms in pond water and called them “animalcules” (protists)

Question 21

Wet Mount Slide

Answer 21

•When a drop of water is applied to the specimen on the microscope slide and the covered with a cover slip

Question 22

Purpose of a Wet Mount Slide

Answer 22

• Many samples look better when placed in a drop of water on the microscope slide
• The water supports the sample and it fills the space between the cover slip and the slide, allowing light to pass easily through the slide, the sample, and the cover slip
• The water helps the cover slip and the sample stay in place due to surface tension and adhesion/cohesion
• The cover slip helps protect the objectives from the specimen

Question 23

How to make a Wet Mount Slide

Answer 23

• Add a drop of water to a slide
• Place the specimen in the water
• Place the edge of the cover slip on the slide so that it touches the edge of the water
• Slowly lower the cover slip to prevent foaming and trapped air bubbles

Question 24

Inverted

Answer 24

• Happens to images while using a microscope
• The image turns upside-down and reverses it
• When moving a slide, the image will appear to move in the opposite direction

Question 25

Moving from Low to High power

Answer 25

• The image will become darker (low to high)
• The field of view becomes smaller (low to high)
• Manipulate the diaphragm to let in more light (low to high)
• Your head/eyes should be to the side of the microscope (low to high)

Question 26

Moving from High to Low poer

Answer 26

• The field of view become bigger (high to low)

* The image will become lighter (high to low)

Question 27

Working distance

Answer 27

•The distance between the stage and your objective

Question 28

micrometer

Answer 28

•1 µm=0.001 mm

Question 29

millimeter

Answer 29

•1 mm=1000 µm

Question 30

the equation to find the size of the specimen

Answer 30

• diameter of field/#that fit across the field

* SPFD/LPFD/HPFD

Question 31

how to calculate the diameter of the high power field

Answer 31

•high power field diameter

=low power field diameter÷(high power magnification/low power magnification)

Question 32

Pre-Focusing

Answer 32

•Carry the microscope by putting one hand on the arm and another on the base
•Make sure the microscope’s arm is facing you
•Put away all books and papers
•Plug in the microscope and turn on the illuminator
•Turn the coarse adjustment knob to lower the stage (or raise the body tube)
•Turn the revolving nose piece until the low power objective (10x) clicks into place
•Slowly adjust the diaphragm to allow enough light through the stage opening while looking through the eye piece
•Center the specimen over the opening on the stage after
placing a slide on the stage (use stage clips if necessary)

Question 33

Focusing

Answer 33

• While looking at the stage from the slide slowly turn the coarse adjustment to raise the stage until the low power objective is at its lowest position, almost touching the slide
• Slowly turn the coarse adjustment while looking through the eye piece to focus the specimen
• Move the slide so the specimen is exactly in the center of the microscope field before turning to high power
• Look at the stage from the side and turn the revolving nose piece to switch to high power
• Make sure the objective doesn’t hit the slide
• While looking through the eye piece, turn the fine adjustment knob no more than 1/2 turn to focus the specimen
• If the image isn’t clear, return to low power and repeat all the steps again

Question 34

Post-Focusing

Answer 34

• When done move the low power objective back into position over the stage and remove the slide from the stage
• Carry the microscope with two hands and return it to the cart