Showing SCALE in biology

Working out scales (of drawings or photomicrographs) is a common exam question in IB papers – usually in the Paper 1 Multiple Choice. It is most simply done with a scale bar. TIPS I think the most useful tip is to make sure that you have some idea of what real size actually should be:…

Surface area to volume ratio – why cells cannot be huge

I hope that this is a fairly straightforward way to show the calculations for working out surface area and volume of a cuboid cell, and then putting the two together to show the all-important surface area to volume ratio. Volume increases faster than surface area, thus the ratio of the two (SA : Vol) becomes smaller…