Uploaded September 2023 | Updated September 2026, 12 hours ago
You can find all my A Level Biology videos fully indexed at freesciencelessons.co.uk/a-level-revision-videos/a-level-biology
In this video, we look at how to measure the rate of respiration using a respirometer. First, we look at how a simple respirometer works in terms of gas volume. We then look at how to carry out the calculation to determine the rate of respiration. Finally, we look at how to address the problem of temperature fluctuation using a more complex respirometer.
You can find all my A Level Biology videos fully indexed at freesciencelessons.co.uk/a-level-revision-videos/a-level-biology
In this video, we look at how to measure the rate of respiration using a respirometer. First, we look at how a simple respirometer works in terms of gas volume. We then look at how to carry out the calculation to determine the rate of respiration. Finally, we look at how to address the problem of temperature fluctuation using a more complex respirometer.



![GCSE Biology Revision Plant Cell Specialisation
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In this video, we look at how plant cells are specialised to carry out their functions. We explore three types of plant cell: root hair cells, xylem cells and phloem cells.
This video is based on the AQA spec. This video may be appropriate for iGCSE / O Level Biology. Please consult your specification. The Amazon link above is an affiliate link. This provides a small commission which helps to support freesciencelessons. The cost remains the same to you. If you prefer not to use this, you can search Amazon for the Freesciencelessons workbooks.
Image credits:
root hairs By Oregon Caves from Cave Junction, USA (Mycorhizae fungus) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons
Cheek cells
https://commons.wikimedia.org/wiki/File:Cheekcells_stained.jpg
Mulletsrokk, CC BY-SA 3.0 https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons GCSE Biology Revision Plant Cell Specialisation](https://i.ytimg.com/vi/8UAl5C2frNQ/mqdefault.jpg)






![GCSE Chemistry Revision Transition Elements (Triple)
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In this video, we look at the transition elements. First we look at the location of the transition elements on the periodic table. We then look at the properties of the transition elements compared with the group 1 metals (alkali metals). This includes their hardness, their melting points, their density, how rapidly they react and the charge on the ion. Finally we look at how transition metals form coloured compounds and how transition metals can be useful as catalysts.
This video is based on the AQA spec. This video may be appropriate for iGCSE / O Level Chemistry. Please consult your specification. The Amazon link above is an affiliate link. This provides a small commission which helps to support freesciencelessons. The cost remains the same to you. If you prefer not to use this, you can search Amazon for the Freesciencelessons workbooks.
Image credits:
Iron
https://commons.wikimedia.org/wiki/File:Two_iron_magnetic_cores.jpg
Anselm Schüler, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons
Iron oxide
https://commons.wikimedia.org/wiki/File:Iron(III)-oxide-sample.jpg
By Benjah-bmm27 [Public domain], from Wikimedia Commons
Manganese chloride
https://commons.wikimedia.org/wiki/File:Manganese(II)_chloride_tetrahydrate.jpg
Chromium chloride
https://commons.wikimedia.org/wiki/File:Chromium(III)-chloride-purple-anhydrous-sunlight.jpg
Benjah-bmm27, Public domain, via Wikimedia Commons
Copper sulfate
https://commons.wikimedia.org/wiki/File:%E1%83%A1%E1%83%9E%E1%83%98%E1%83%9A%E1%83%94%E1%83%9C%E1%83%AB%E1%83%98%E1%83%A1_%E1%83%A1%E1%83%A3%E1%83%9A%E1%83%A4%E1%83%90%E1%83%A2%E1%83%98_%E1%83%9E%E1%83%94%E1%83%9C%E1%83%A2%E1%83%90%E1%83%B0%E1%83%98%E1%83%93%E1%83%A0%E1%83%90%E1%83%A2%E1%83%98.jpg
Vano3333, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons GCSE Chemistry Revision Transition Elements (Triple)](https://i.ytimg.com/vi/A5RpVT1WA8E/mqdefault.jpg)