What is the best explanation for why this coiling takes ? ?

Coiling might be an adaptive process which was developed thru because of the presence of selection forces.
adaptations are the result of evolution in different living organisms. this process occurs amazingly through gene mutation but it takes a very long period in time. adaptation processes occur to species survive and thrive in the ecological balance of life.

An autotrophic protist - they can perform photosynthesis and mainly consist of unicellular algae. they can be divided into number of systematic group according to the shape of their cell and the type of photosynthetic pigments they use.