Bell Ringer: 1. What are cell membranes made of? 2. What happens to a cell if it is placed in salt water (hypertonic solution)? 3. What is the function of the ribosome? 4. Where does aerobic respiration take place in plant and animal cells? 5. Which organelle controls the cell? 6. What is the term for water moving through a membrane? 7. How does oxygen(gas) pass into or out of a cell?

Using the Microscope

Why does T-Rex hate push ups?

Microscopes Devices that produce magnified images of structures that are too small to see with the unaided eye.

Type of Microscope we use! Compound Light Microscope: produces magnified images by focusing visible light rays. Can magnify images up to 1,000x.

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Eye Piece The part that you look through to view the specimen. ◦ Has a 10x magnification

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Arm The basic frame of the microscope to which the base and stage are attached.

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Coarse Adjustment Knob The first device for focusing. Used when the scanning (4x)objective is in place.

Fine Adjustment Knob After roughly focusing with the coarse adjustment knob, turn the fine adjustment knob to sharply focus the image.

Base This is the rectangular part that houses the light.

Objectives The component that magnifies the image of the specimen. There are three objectives: ◦ Scanning(4x), ◦ Low Power(10x), ◦ High Power(40x).

Nosepiece The revolving unit that carries the objectives.

Body The component that houses the prisms.

Stage The table of the microscope where the slide or specimen is placed. Stage Clips: hold the slide in place.

Diaphragm Disc The wheel-shaped device attached to the underside of the stage that allows you to change the amount of light coming through the slide.

Steps for Focusing a Microscope 1. Turn the nosepiece until the scanning objective is in viewing position. 2. Using the coarse adjustment focus the specimen to sharp image. Use the fine adjustment to get the sharpest image. 3. While looking at the stage, turn the nosepiece to the desired objective making sure it does not strike the slide. 4. Adjust the focus using only the fine adjustment knob.

Rules for use and care of the Microscope 1. The microscope is to be carried with one hand grasping the arm and the other supporting (under) the base. 2. No student is to attempt to dismantle any part of a microscope. 3. No student is to clean any glass component of a microscope. Ask a teacher to do the cleaning. 4. Set the microscope down on the counter gently about six (6) inches from the edge. 5. Wipe all liquids and spills from the slide before placing it on the stage. 6. Do not leave slides on the stage or counter after using them. 7. Never use the coarse adjustment knob when viewing a specimen with the objectives set on high power.

Making a Slide Wet Mount: 1.Obtain a very thin sample of the specimen. 2.Place the specimen on the center of the slide. 3.Place one drop of water on the specimen. 4.Touch one edge of the coverslip down at a 45 angle. 5.Gently lower the coverslip being careful not to trap air bubbles. 6.Remove excess water with a paper towel.

Staining Staining the sample allows you to see samples in better contrast. This is especially useful for clear specimens. Wicking Method: