Last week, we discussed a very big bacterium, one you can see with your naked eye! But back in high school we all learned that bacteria and prokaryotes in general were pretty simple cells and were definitely smaller than our cells. While we've found a lot of examples that push back against this idea, there is a fundamental truth behind it -- a simple cell has definite physical constraints on how big it can grow. What are those constraints? And how do these giant bacteria (and our own cells) get around these problems?
References:

https://royalsocietypublishing.org/doi/10.1098/rsif.2008.0014
http://www.math.uchicago.edu/~lawler/reu.pdf
https://www.science.org/content/article/largest-bacterium-ever-discovered-has-unexpectedly-complex-cells