Biology Lab Exercise 4 Vocabulary

Front 1

Exercise 4

Back 1

The Microscope

Front 2

Part A

Back 2

Care and Use of the Compound Microscope

Front 3

Handling Microscope

Back 3

1. Always carry the microscope upright with two hands: one hand on the base, and one hand on the arm. 2. Make sure your workbench is free of clutter before you place the microscope on the bench. 3. Do not drag or shove the microscope across the lab. 4. Always lift the microscope to move or turn it.

Front 4

Preparing Microscope for Storage

Back 4

1. The scanning objective lens is in position above the stage aperture. 2. The mechanical stage has been positioned so that the stage arm is flush with the right side of the stage. 3. The cord is wrapped around the holder and secured. 4. The stage has been adjusted to midpoint.

Front 5

Part B

Back 5

Magnification

Front 6

Total Magnification

Back 6

Magnification of the Ocular lens (10x) X Magnification of the Objective lens

Front 7

Three Objective Lenses

Back 7

Scanning 4x
Low Power 10x
High Dry Power 40x

Front 8

Part C

Back 8

Working Distance and Diameter of the Field of View

Front 9

Part C-1

Back 9

Working Distance

Front 10

Working Distance

Back 10

The distance between the stage and the objective lens. As magnification increases; it decreases.

Front 11

Part C-2

Back 11

Diameter of the Field of View

Front 12

Field of View

Back 12

The extent of the visible image field that can be seen.

Front 13

Formula for Calculating Diameter of Field of View

Back 13

M1 X DFV1 = M2 X DFV2

Front 14

Diameter of the Field of View

Back 14

As magnification increases; it decreases.

Front 15

Part D

Back 15

Estimation of Cell Size

Front 16

Size of Cell

Back 16

= DFV/# of cells to fill the DFV

Front 17

Part E

Back 17

Preparation of Wet Mounts and Replacement Staining

Front 18

Procedure for Creating Wet Mount

Back 18

1. Obtain a clean glass slide and coverslip.
2. Place one or two drops of water on the slide.
3. Obtain specimen and prepare as needed.
4. Place specimen in water.
5. Carefully position the coverslip by placeing one edge of it down first and then lowering the other side. Try to minimize the number of air bubbles that form.
6. The coverslip should not be floating on the slide. If it does, remove the coverslip and excess water and start over.

Front 19

Part E-2

Back 19

Onion Epidermis

Front 20

Procedure for Replacement Staining Technique

Back 20

1. Place a few drops of IKI on the slide against one edge of the coverslip.
2. Place the smooth edge of a single layer of paper towel up against the opposite edge of the coverslip. The paper towel will pull the water out from under the coverslip and the stain (IKI) will replace the water.
3. Continue the process, adding more IKI if necessary, until the stain covers the area under the coverslip.
4. Wait a few minutes and then place distilled water on one side of the coverslip and draw the excess IKI out with the paper towel. The water then replaces the IKI.
5. Once all the yellow IKI has been removed, dry the upper surfaces of the slide.

Front 21

Part E-3

Back 21

Cheek Cells

Front 22

Nucleus

Back 22

The chromosome containing organelle of a eukaryotic cell.

Front 23

Cytoplasm

Back 23

The contents of the cell, exclusive of the nucleus and bounded by the plasma membrane.

Front 24

Plasma Membrane
(Cell Membrane)

Back 24

The cell’s outer membrane made up of a two layers of phospholipids with embedded proteins. It separates the contents of the cell from its outside environment, and it regulates what enters and exits the cell.

Front 25

Part E-4

Back 25

Pond Water

Front 26

Techniques for Viewing Living Microorganisms

Back 26

Staining techniques will kill the specimen. Can add Protoslo to wet mount to slow movement of microorganism.

Front 27

Part F

Back 27

The Dissecting Microscope

Front 28

Dissecting Microscope

Back 28

Lower magnification used for larger specimens. As magnification increases, DFV increases.

Front 29

Part G

Back 29

Use of a Dichotomous Key

Front 30

Dichotomous Key

Back 30

A reference tool where a series of choices between alternative characters leads progressively to the identification of the species.

Front 31

Procedure for Using Dichotomous Key

Back 31

1. Obtain specimen.
2. Examine using microscope.
3. Use the dichotomous key provided to decide which order your specimen belongs in.
4. Begin with couplet 1 and determine which of the two statements more closely fits your specimen.
5. When you have decided which of the two statements applies to your specimen, move to the couplet pair that is listed at the end of that statement.
6. Determine which of the two statements again more closely fits your specimen.
7. Continue to work your way through the key, deciding between pairs of statements, until you arrive at a name.