Created this for a school project, there is another model (https://www.thingiverse.com/thing:1820314) but when printed is very loose. 

I created the chromosome in Fusion 360 and split it with 0.2 mm. It is a bit tight to assemble but it holds together, some pieces only fit in one direction.

There is a large and medium size chromosomes, if you find it useful and need the smaller one, I could produce it.