Plant roots grow towards water. What type of tropism is this?

What is meant by hydrotropism? Give an example.

$(a)$ How are the movement of leaves of touch-me-not and the growth of a stem towards light different?
$(b)$ What is chemotropism? Give one example.
$(c)$ What is tropism?

In figures $(a)$,$(b)$ and $(c)$,which appears more accurate and why?

Which tropic movement is responsible for the growth of pollen tubes towards ovules?

The opening of a tulip flower is an example of which type of movement?