Microscopy
This practical lesson covers:
- How to prepare microscope slides to show the cells in onion skin and cheek cells
- How to use a light microscope to observe, draw, and label biological specimens
Using a light microscope to observe, draw, and label plant cells in an onion skin |
Aim:
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Background information Microscopy is an essential biological technique for studying cellular structures. A light microscope uses visible light and lenses to magnify small objects like cells. In this practical, you will prepare and observe onion skin cells and animal cheek cells. Using iodine solution to stain the cells, enhances the visibility of certain cell components, making structures like cellulose in cell walls and any starch present, more visible. |
What is the purpose of switching to a higher power lens during microscopy?
to rotate the nosepiece
to see the cells more clearly
to increase the magnification
to change the focus of the microscope
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What is the purpose of using the fine adjustment knob when observing cells at low power?
to change the focus of the microscope
to adjust the lens so that it is nearly touching the slide
to rotate the nosepiece
to increase the magnification
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What is the product of the eyepiece magnification and the objective magnification if the eyepiece magnification is x10 and the objective magnification is x40?
x10000
x400
x4000
x50
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What is the purpose of the microscope slide coverslip?
to adjust the focus of the microscope
to increase the magnification of the microscope
to hold the biological specimens in place
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Why is iodine solution commonly used as a stain in onion cell microscopy?
it binds to and stains starch
it gives the cytoplasm a blue colour
it specifically highlights cell membranes
it reacts with proteins in the cell nucleus
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What does methylene blue solution bind to in cheek cell microscopy?
nucleic acids like DNA
chloroplasts
cell membranes
cytoplasm
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