Microscopes and magnification GCSE combined science Edexcel biology higher

Calculate.

What is the word equation for magnification?

Magnification image size/actual size.

What is the another equation for magnification?

Total magnification=eyepiece magnification times by objective magnification.

Describe how to prepare when using a microscope.

Peel a thin layer of cells from an onion.

Place it on a glass slide.

Add an iodine stain so that you can see the cells clearly.

Carefully, cover it with a coverslip to avoid air bubbles and drying.

Carefully clip it with a clipper and put it on the stage.

Turn the course focusing wheel until you see the cells clearly.

Turn the fine focusing wheel so that you can see the cells in detail.

Why should you try and avoid bubbles when adding the cover slip?

It will interfere with your experiment.

Why do you stain the cheek cells?

To be more visible.

Why should you wear goggles when making the slide?

To protect yourself from iodine.

Why did you use iodine when preparing your onion slide?

So that you can see the cells clearly.

What is the purpose of the course focusing wheel on a microscope?

Brings the stage up and down.

What is the difference between the eyepiece lens and the objective lens?

The eyepiece lens is responsible for further magnifying the image produced by the objective lens. The objective lens is responsible for collecting light from the specimen and producing an image that the eyepiece lens magnifies.

What is the lowest powered objective lens on a microscope?

x4 objective lens.

What is the highest powered objective lens?

100x

What is the differences between a light microscope and an electron microscope?

Light microscope are used to study living cells and for regular use when relatively low magnification and resolution. Magnify up to 1,000 times and it is less expensive. Electron microscope provides a higher magnification and higher resolution images but cannot be used to view living cells and it can magnify up to 2,000,000,000 times, it is more expensive.

When was light microscope invented?

In the 1600s.

When was electron microscope invented?

In the 1930s.

What are the advantages of light microscope?

Accessibility:widely available in classrooms.

Cost is cheap.

They can produce colour images which can be easier to interpret.

They serve as an educational tool.

What is the advantages of electron microscope?

Higher magnification and resolution.

Allows detail observation of subcellular cells.

Useful for studying organelles and other tiny structures that are not visible with light microscope.

What are the disadvantages of electron microscope?

Expensive.

Require a vacuum and metal coating which can damage and damage living tissues.

Cannot be used on living cells.

What are the disadvantages of light microscope?

Less resolution and magnification.

What are the two types of electron microscopes?

The transmission electron microscope and the scanning electron microscope.

What is the transmission electron used for?

Used to examine thin slices or section of cells or tissues.

What is scanning electron microscope used for?

Can be use to examine the surface structure of specimen.