Uploaded June 2023 | Updated September 2026, 9 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 the idea of surface area to volume ratio. First we explore how unicellular organisms can rely on diffusion through their cell membrane for transferring molecules in and out of the cell. We then look at what is meant by the surface area to volume ratio. I show you how to calculate the surface area to volume ratio and give you an example to try yourself. Finally, we look at how multicellular organisms have evolved to exchange substances.
This video is aimed at the UK A Level Biology specifications. Students studying International A Level Biology will need to check their specification.
Image Credits:
Amoeba
commons.wikimedia.org/wiki/File:Amoeba_proteus_another_form.jpg
SmallRex, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons
Flatworm
commons.wikimedia.org/wiki/File:Yellow_papillae_flatworm_(Thysanozoon_nigropapillosum)_(cropped).jpg
Betty Wills, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons
Cod
commons.wikimedia.org/wiki/File:Gadus_morhua-Cod-2-Atlanterhavsparken-Norway.JPG
Photo: Hans-Petter Fjeld, CC BY-SA 2.5 creativecommons.org/licenses/by-sa/2.5, via Wikimedia Commons
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 the idea of surface area to volume ratio. First we explore how unicellular organisms can rely on diffusion through their cell membrane for transferring molecules in and out of the cell. We then look at what is meant by the surface area to volume ratio. I show you how to calculate the surface area to volume ratio and give you an example to try yourself. Finally, we look at how multicellular organisms have evolved to exchange substances.
This video is aimed at the UK A Level Biology specifications. Students studying International A Level Biology will need to check their specification.
Image Credits:
Amoeba
commons.wikimedia.org/wiki/File:Amoeba_proteus_another_form.jpg
SmallRex, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons
Flatworm
commons.wikimedia.org/wiki/File:Yellow_papillae_flatworm_(Thysanozoon_nigropapillosum)_(cropped).jpg
Betty Wills, CC BY-SA 4.0 creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons
Cod
commons.wikimedia.org/wiki/File:Gadus_morhua-Cod-2-Atlanterhavsparken-Norway.JPG
Photo: Hans-Petter Fjeld, CC BY-SA 2.5 creativecommons.org/licenses/by-sa/2.5, via Wikimedia Commons
