Uploaded January 2024 | Updated September 2026, 9 hours ago
In this video, we look at rod cells and cone cells as light receptors in the retina. First we explore the structure of rod cells. We look at how rod cells show retinal convergence and why this leads to low visual acuity. We then explore cone cells and see why cone cells lead to high visual acuity and colour vision.
In this video, we look at rod cells and cone cells as light receptors in the retina. First we explore the structure of rod cells. We look at how rod cells show retinal convergence and why this leads to low visual acuity. We then explore cone cells and see why cone cells lead to high visual acuity and colour vision.
![GCSE Chemistry Revision Nanoparticles (Triple)
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In this video, we look at nanoparticles. First we explore the relative sizes of particles and look at what is meant by a micrometre and a nanometre. We look at what is meant by coarse particles, fine particles and nanoparticles. We then look at the surface area : volume ratio of particles and use this to explain why nanoparticles are useful. Finally, we explore the potential negative effects of nanoparticles.
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Image credits:
Pills (By MorgueFile : see [1], CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=1570359)
Suncream (By Simon Speed (Own work) [Public domain], via Wikimedia Commons)
Electronics (Public Domain, https://commons.wikimedia.org/w/index.php?curid=121803)
Deodorant (By No machine-readable author provided. Dickbauch~commonswiki assumed (based on copyright claims). - No machine-readable source provided. Own work assumed (based on copyright claims)., Public Domain, https://commons.wikimedia.org/w/index.php?curid=500634)
Cosmetics (By Evi Michailidou - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=19125512)
Catalyst (By Seaterror (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons) GCSE Chemistry Revision Nanoparticles (Triple)](https://i.ytimg.com/vi/VxKHzt93h-0/mqdefault.jpg)



![A Level Biology Revision (Year 13) The Human Brain
In this video, we look at the human brain. We explore the structure of the human brain and then the functions of the different parts. This includes the cerebrum (and cerebral cortex), the cerebellum, the medulla oblongata, the hypothalamus and the pituitary gland.
Image credits:
Peripheral and central nervous system
https://commons.wikimedia.org/wiki/File:Nervous_system_diagram_unlabeled.svg
Medium69, Jmarchn, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons
The brain
https://commons.wikimedia.org/wiki/File:Diagram_showing_the_brain_stem_which_includes_the_medulla_oblongata,_the_pons_and_the_midbrain_(2)_CRUK_294.svg
Cancer Research UK, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons
MRI of brain
https://commons.wikimedia.org/wiki/File:MRI_Brain_T2_Axial_(16).jpg
511KeV, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons
Hemispheres
https://commons.wikimedia.org/wiki/File:Cerebral_hemisphere animation.gif
Polygon data were generated by Database Center for Life Science (DBCLS), CC BY-SA 2.1 JP https://creativecommons.org/licenses/by-sa/2.1/jp/deed.en, via Wikimedia Commons
Lobes of the brain
https://commons.wikimedia.org/wiki/File:Lobes_of_the_brain_NL.svg
Henry Vandyke Carter, Public domain, via Wikimedia Commons
Auditory cortex
https://commons.wikimedia.org/wiki/File:Primary_auditory_cortex lateral_view.png
Polygon data were generated by Database Center for Life Science(DBCLS)[2]., CC BY-SA 2.1 JP https://creativecommons.org/licenses/by-sa/2.1/jp/deed.en, via Wikimedia Commons
Visual cortex
https://commons.wikimedia.org/wiki/File:BA17_Primary_visual_cortex medial_view.png
Polygon data were generated by Database Center for Life Science(DBCLS)[2]., CC BY-SA 2.1 JP https://creativecommons.org/licenses/by-sa/2.1/jp/deed.en, via Wikimedia Commons
Primary motor cortex
https://commons.wikimedia.org/wiki/File:Ba4.png
Washington irving, CC BY-SA 3.0 http://creativecommons.org/licenses/by-sa/3.0/, via Wikimedia Commons
Trace from patient with disorder of cerebellum
https://commons.wikimedia.org/wiki/File:Thomas-fig67-p124.png
Figure 67of the book Cerebellar functions by André Thomas
uploaded by Looie496; original artist unknown A Level Biology Revision (Year 13) The Human Brain](https://i.ytimg.com/vi/WRw27NQzX-A/mqdefault.jpg)





