Mrs. McCrea’s Biology Classroom

9/19/11

Microscope Lab

Who am I???

Hans and Zacharias Janssen share a father, and a son relationship; Hans being the father, and Zacharias being the son. These men are Dutch and they are known for building the first compound microscope. It is mostly believed that Zacharias was the first man to build the microscope, but he was at such a young age when the compound microscope was discovered, that most historians agree that his father, Hans had a significant role in the creation of the compound microscope. The microscope was created in the year 1590.

Essential Question: How do scientists use microscopes to view small living and non-living objects?

Goals:• Identify the parts of a microscope and

describe their functions.

• Observe prepared slides under a microscope.

• Focus a virtual microscope by following step by step instructions.

Name parts of the microscope! Let’s see how many parts you can name in 30

seconds!

Parts of the Microscope

FUNCTIONS!!!

A. the lens at the top that you look through.  They are usually 10X or 15X power.

B. rotating disk under the stage that controls light going through specimen

C. For focusing under low magnification

D. The shortest lens is the lowest power, the longest one is the lens with the greatest power (4X, 10X, 40X and 100X powers)

E. For focusing under high magnifaction

1.Fine Focus

2.Course Focus

3.Diaphragm

4.Objective lenses

5.Eye piece

DO NOW!• Answer the question below in your team! Be sure

to write your answer on the whiteboard.

If your eye eyepiece lens is 10x and your objective lens is 40x, what is the TOTAL MAGNIFICATION of the object you are viewing under your

microscope?

1.10 Virtual Microscope Lab

• Your lab report is found in Doc Sharing under Modified Labs.

• Yesterday, you should have answered your pre-lab questions for homework.

Pre-Lab Questions

ANSWER THESE QUESTIONS AS YOU FOLLOW THE TOUR!

1. What objective lens power should you start with always? Circle the correct answer.

4x (scanning lens) 10x(low power) 40x(high power)

2. Which focus knob moves the stage quickly?

3. Which focus knob moves the stage slowly? 

4. Which button do you press to look through the virtual microscope?

5.  Were you able to adjust the ocular lenses so you merged the two circles?

6. Where should the center of the specimen be?

Let’s Practice Focusing the

Virtual Microscope!

Remember to look at the Post Lab questions before you start so you can look for answers as

you go.

Lab Questions

1. How did the letter “e” appear under the microscope?

2. Describe what the onion root tip looks like under the 40x lens.

3. Describe what the bacterial capsule looks like under the 10x lens.

4. Describe what the cheek smear looks like under the 40 x lens.

1. Turn on microscope light

2. Move the rheostat to 10 (light brightness)

3. Choose the slide in upper right hand corner.

4. Make sure scanning lens is in place (4x)

5. Center the specimen on the stage using the knobs on the right hand side (top) of the microscope.

6. Move stage to top position using the knobs on right hand side (bottom).

7. Click on “switch views” at top of checklist.

8. Adjust the ocular lenses using the eyepieces at top by dragging until circles overlap.

9. Using the course adjustment, focus the specimen.

10. Then use the fine adjustment to focus more precisely. (The red circle will be focused)

11. Adjust lighting using iris diaphragm if needed (so check appears).

12. Change between the four objective lenses using the rotating nosepiece in bottom left corner.

13. Once finished with this slide, move on to next slide by switching views.

Extension

Parts of the Microscope:

http://www.quia.com/quiz/1480383.html?AP_rand=216640179

Your TO DO list:

1. Complete Microscope lab and put in dropbox.

2. Read lesson 1.11 and take notes on guide

3. Session tomorrow at

TODAY’S PARTICIPATION 9/19/11:To earn your points for today,

please place the function of the course adjustment in the dropbox labeled Participation 9/19-9/23.