Date: September 24, 2015 (double periods)

Aim #8: How do scientists make detailed observations?

HW:1) Complete Article Review (Measuring Horses)2) Textbook HW #3 (Section 1-4) due Friday 9/253) UNIT 1 TEST- NEXT WEEK THURSDAY/FRIDAY

Do Now: Warm-Up Notebook

Date Title of Activity Page #9/24 Metric Prefixes18

Date: September 24, 2015

Aim #9: How do scientists make measurements with a microscope?

HW:1) Complete packet pages 22 & 232) Textbook HW #3 (Section 1-4) due Friday 9/253) Pill Bugs please 4) UNIT 1 TEST- NEXT WEEK THURSDAY/FRIDAY

Do Now: Warm-Up Notebook

Date Title of Activity Page #9/24 Metric Prefixes18

1. What is a compound microscope: Two lenses:

Objective lens

Ocular/eyepiece lens

2. Why is this better than a magnifying glass?

Larger magnification!

To calculate total magnification:

multiply objective power by ocular power

Let’s try some: What is the total magnification of

the following microscopes?

10X ocular and 40X objective = 400X 10X ocular and 10X objective = 100X

3. What are the parts of the microscope ?A. Eyepiece (ocular)

B. Body tube

C. Objective lens

D. Light source

E. Adjustment

F. Arm piece

Not labeled: diaphragm

Part Function

A. Eye piece where you look through to see the image of your specimen (ocular lens)

B. Body tube the long tube that holds the eyepiece and connects it to the objectives

C. Low power objective used for low power magnification of the specimen

High power objective Used for high power magnification of the specimen (not labeled)

D. Light source of light usually found near the base of the microscope; makes the specimen easier to see

E. Fine adjustment small, round knob on the side of the microscope used to fine tune the focus of your specimen after using the coarse adjustment knob

Coarse adjustment used for focusing on low power only (not labeled)

F. Arm piece part of the microscope that is grasped when one carries the microscope

Base supports the microscope (not labeled)

Diaphragm controls the amount of light going through to the specimen (not labeled)

Stage holds slide for viewing specimen (not labeled)

Stage clips on top of the stage which hold the slide in place (not labeled)

Nosepiece the rotating part of the microscope at the bottom of the body tube; it holds the objectives (not labeled)

10. Objects appear upside down and reverse under the microscope. What would the letter

“F” look like under the microscope?

11. Measuring with a Microscope Estimate the # of times

the object fits across your field of view

Divide the total diameter by this number

Example:

4000/5 = 800 µm