Do now Directions: Describe three differences between the STRUCTURES of Animal and Plant Cells. 1______________________________ 2_______________________________ 3______________________________
List the three parts of the cell theory. 1______________________________ 2_______________________________ 3______________________________
Parts of a Compound Microscope Objective: Microscope care Identify parts of the microscope Calculate magnifications
Always carry with 2 hands Microscope Care Always carry with 2 hands Only use lens paper for cleaning Do not force knobs Keep objects clear of desk and cords Teacher demonstrates how to hold the microscope, where the lens paper is located and how to use it. Students will be invited to turn the knobs and observe the stage as it moves up and down. Teacher will demonstrate how to store the microscope.
Compound Microscope A microscope is a very powerful magnifying glass A microscope helps you see things like cells up close
Eyepiece View the specimen through the eyepiece
Stage Clips & Objectives Stage clips hold the slide in place Low power objective is used to focus the microscope (short & fat) High power objective is used to view details of a specimen
Coarse Adjustment, Fine Adjustment, & Base Coarse adjustment focuses adjustment Fine adjustment fine tunes & gives detailed focus(usually smaller than coarse adjustment knob) Base is where the microscope rests
Stage Stage is part where the slide rests Mirror (or light source) directs light upwards onto the slide.
Diaphragm Diaphragm allows light in
Arm Arm is the part where you carry the microscope
Nosepiece Nosepiece is the rotating device that holds the objectives (lenses)
Ocular & Objective lenses Ocular lens – The lens that is in the eye piece. Has a magnification of 10x. Objective lens – The 3 lenses located on the nosepiece. Each lens has a different magnification. The total magnification of an image is calculated by multiplying the magnification of the ocular by the magnification of the objective.
Total magnifications ( Ocular lens = 10x ) Objective Magnification Total Magnification Low 4X 40X Medium 10X 100X High 400X
Can you name the parts of a compound microscope?
Answers base mirror (light source) diaphragm stage stage clips low power objective lens high power objective lens nosepiece arm fine focus knob body tube coarse focus knob eyepiece
Using the Microscope Place the Slide on the Microscope Use Stage Clips Click Nosepiece to the lowest (shortest) setting Look into the Eyepiece Use the Coarse Focus Give students a slide from the “common things” set, each student will practice focusing and changing objectives.
Using High Power Follow steps to focus using low power Click the nosepiece to the longest objective Do NOT use the Coarse Focusing Knob Use the Fine Focus Knob to bring the slide Have students exchange slides so they can look at different things, walk them through using the high power objective to focus slides. Emphasize not using the coarse objective during this process, as it will crack the slides. What can you find on your slide?
FIELD OF VIEW
DO NOW: Is the field of view larger or smaller under high power? Explain.
Field of View: Measurement of the area that can be seen. How much can you see when you are 1 inch away from something? How much can you see when you are 2 inches away from something? How much can you see when you are 3 inches away from something?
How do we know how wide the field of view is? We have to measure it while looking through the microscope. 4mm 4mm
2 mm
4 mm
how many boxes wide is the field of view? 3.5mm
What is the diameter of each field of view? B 5.5 3 C D 1.5 2
4mm 1mm How big is the Paramecium? When you place the grid on the stage and look at it under 40x, this is what you see. When you look at a paramecium under 40 x, this is what you see How big is the Paramecium? 4mm 1mm
The protist is about 2.5 mm. 5mm
Number that can fit across Size of Object Size of object = Field of View Number that can fit across
9mm
Field of view Number that can fit 3mm 3mm 3mm 9mm 3 = 3mm 9mm
Field of view Number that can fit 3mm 5 0.6 mm 3mm
Which has a larger FOV? 100x 400x
Do Now Write down your homework Put away everything except your lab and a pencil Answer the prelab questions
Pre Lab Questions: What are the three different total magnifications on our microscopes? 40 100 400
What is “Field of View”? Measurement of the area that can be seen under the microscope.
What do you predict will be the relationship between power of lens and size of field of view?
Scanner Objective Lens Width of Diameter of FOV= 40 X Low Power Objective Lens 100 X High Power Objective Lens 400 X Slide A Grid Diameter of FOV (# of Boxes) _________boxes Width of Diameter of FOV= ___________mm 4 1.5 .5 4 1.5 .5
Exit Ticket: (tail not included) How wide is the organism?
Do Now Describe the proper way to find a specimen on high power.