Itty Bitty City: the Microscopic World in a Drop of Pond Water

Microscope Lab

Itty Bitty City: The Microscopic World In A Drop Of Pond Water

Purpose: To examine the variety of living organisms in pond water.

Materials: Microscope, pond water, dropper, paper towel, microscope slide and cover-slip, pencil, eraser, white unlined paper, and lab sheets.

Instructions: Making a wet mount slide

1. Squeeze the bulb of the pipette firmly, BEFORE inserting into culture. Pull from the bottom

2. Put one drop of culture on the slide, this is usually sufficient unless specified differently

3. Observe the drop of pond water under Low Power to scan and find the organisms. Medium Power is useful once you have found something to determine.

4. If the organisms are moving too fast and therefore difficult to observe; add one drop of Methyl Cellulose to a drop of culture on the slide. These procedures will slow the organisms.

YOU MUST BE PATIENT FINDING THEM, IT IS WORTH WHILE

Observations

1) Locate and diagram 2 organisms on the sheet provided according to the Biological Diagram Rubric.

2) Number each diagram and be sure to include all necessary information (See Biological Diagram Rubric).

3) On a separate piece of loose-leaf, record the following information for each diagram:

A brief description of the organisms

- Color

- Shape as it appears to you

- Movement pattern: is it by cilia? or flagella?

- Any feeding if observed

- Size of organism (See microscope calculation sheet for reference).

Conclusions

Put answers on a separate sheet and turn in with lab drawings and observations

1. Why was it necessary to begin your observation using the low power objective first?

2. How did you distinguish between living and non-living matter?

3. From what observation can you infer that pond water organisms expend energy?

4. What characteristics might be used to distinguish between plant like and animal like organisms?

Final Product Checklist

Did you remember to include:

1. A title page

2. Rough Biological Drawing

3. Good Biological Drawing (lab specimen)

4. Observation Question answered

5. Conclusion Questions answered

6. Calculation page (both sides complete)

7. Labelled Microscope Sheet

Sample Title Page

Name______Date ______

RUBRIC FOR BIOLOGICAL DIAGRAMS

Only pencil used P F

Only blank paper is used P F

Leave a 1 cm margin /2
Name printed on top right of page /2
Ruler used for (horizontal) labeling /2
Labels are printed to the right P F
Measurement at longest point /2
Bottom right indicates subject /2
No shading is used /1
Stipples are used appropriately /1
Objects are in proportion & include only what is seen /6

Clear and unbroken lines /2

TOTAL MARK /20

Sample Biological Drawing

Name______Date ______

Microscope Calculations for Science 10

1. What is the MAGNIFICATION of the OCULAR LENS?

The magnification of the ocular lens is ______X

2. Calculating the MAGNIFICATION of the MICROSCOPE.

Magnification of microscope = ocular lens x objective lens

a) Magnification of microscope (4X objective) ___ x ___ = _____

b) Magnification of microscope (10X objective) ___ x ___ = _____

c) Magnification of microscope (40X objective) ___ x ___ = _____

3: What is the ACTUAL SIZE of the SPECIMEN you looked at with the microscope?

Actual size of specimen (mm) = Field of view (see table above)
# of specimens to fit across field of view
Magnification of Microscope Field of view
40X (low) 4.2 mm
100X (medium) 1.72 mm
400X (high) 0.42 mm

Example of Calculations for Science 10

Using the 4X objective of a compound light

microscope, you view the picture at the side.

a) What is the magnification of the microscope?

b) What is the actual size of the specimen?

Complete calculations, including all formulas and units.

A. Using the 10X objective of a compound light

microscope, you view the picture at the side.

a) What is the magnification of the microscope?

b) What is the actual size of the specimen?

B. Using the 40X objective of a compound light

microscope, you view the picture at the side.

a) What is the magnification of the microscope?

b) What is the actual size of the specimen?

Name______Date ______

Parts of the Compound Light Microscope

Parts of a Compound Light Microscope

Stage: / Supports the slide.
The central opening in the stage allows light to
pass through.
Stage Clips: / Keep the slide in position
Diaphragm: / Regulates the amount of light reaching the object
being viewed.
Ocular Lens / Viewing (10X)/Eyepiece
Coarse Adjustment knob: / Moves the body tube up or down so you can get
the specimen in focus. It is used with the low
power objective only!
Fine Adjustment Knob: / Used with med or high power to get the specimen
in sharper focus
Arm: / Part of the microscope you carry the microscope with
Base: / Supports the microscope
Light Source: / Provides light making it easier to view the specimen
Objective: / Low (4X), Medium (10X) and High (40X)
Attached to the revolving nosepiece
Body Tube: / The long tube that holds the eyepiece and connects it
to the objective

Science 10: Microscope Lab Marking Sheet

Name: ______

1 / Practice Biological Diagram / 10 marks
2 / Biological Drawing of Specimen (Best) / 20 marks
3 / Observation Question (1) / 5 marks
4 / Conclusion Questions (5) / 15 marks
5 / Calculation Page / 10 marks
6 / Parts of a Microscope Labelled Diagram / 5 marks
Total Value for Microscope Lab / 65 marks

Science 10: Microscope Lab Marking Sheet

Name: ______