Induction Week

Aims:

To give you a taster of what A-Level biology is all about

To teach you the first week of A-level biology content(this will be of suitable challenge to bridge the GCSE/AS gap)

This content will not be re-taught at the beginning of September

In the first two weeks of September you will:

be taught the remaining content to AS levelbe tested on the content taught either side of the summer breakassessed for your suitability for A level biology

Biology A Level - Induction Week:Cells and the Microscope

Learning OutcomesDescribe and interpret drawings and photographs of eukaryotic cells as seen under an electron microscope and be able to recognise the following structures: nucleus, nucleolus, nuclear envelope, rough and smooth endoplasmic reticulum (ER), Golgi apparatus, ribosomes, mitochondria, lysosomes, chloroplasts, plasma (cell surface) membrane, centrioles, flagella and cilia.

Outline the functions of the structures listed above.Outline the interrelationship between the organelles involved in the production and secretion of proteins (no detail of protein synthesis is required).

Calculate the linear magnification of an image.

Studying Cells

Microscopy is a key technique used to help understand the ultrastructure and function of cells and cell organelles.

Light microscopyElectron microscopy

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How small is a cell?

Microscopy - Theory

Magnification:

Making things look bigger

Resolution:

The capacity to distinguish to points.

Wavelength:

As wavelength increases, resolution decreases.

THIS WILL BE IN YOUR INDUCTION TEST!!!!

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Electron microscopes

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Preparing a specimen for microscopy

Electron microscopes contain a vacuum as air particles would interfere with the beam of electrons.

Optical microscopes can be used to view living specimens. Coloured dyes (stains) can be used to make specific structures more visible under a light microscope.

Water boils at room temperature in a vacuum, so the specimen must be dried out completely (dead).

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Microscope characteristics

Using a light microscope

https://www.youtube.com/watch?v=jP9HtcAvGDk

Making an onion cell slide

http://www.youtube.com/watch?v=GHnndVuaync

Estimating the size of cells

Using a stage graticule

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Virtual microscope