Write the mechanism of bending of flagellum and explain effective and recovery strokes.

* Bending movement of flagellum is due to sliding of microtubules in doublet.
* The dynein arms attach to the adjacent microtubule and pull them.
* For this they use energy provided by ATP.
* The doublets slide past each other and cause the bending of flagellum.
* The movement of flagella is a side wise lash movement which consists of two strokes.
* Effective stroke – flagellum becomes rigid and beats against the water. This moves the
animals forwards.
* Recovery stroke – flagellum reaches to its original position.