What advantage does Trypanosoma's shape provide?

Answer 1

Trypanosomes come in essentially two shapes:

long and slender: this is the form it takes on maturity. It is better for motility and use of its flagella. In this form it can move about in the blood stream of the human host and can reproduce.

short and stumpy: this is the form it takes during the part of its life cycle in the tsetse fly. It is relatively immotile and does not reproduce in this form. It is compact.