What organisms exhibit the most precise length scales? E.g. are there trees with rings that are of very precise thickness, or single celled organisms which are all very nearly the same length?
In particular, it seems to me that most lengths in nature are precise only to about the 10% level. Are there any organisms which exhibit length scales considerably more precise than this?
(Bonus points if you can tell me the most precise mass scales in nature, too.)
PS: This question is partially motivated by ongoing studies by physicists as to the origin of length scales in biology. See this paper for an example.