Question

Why is the movement of sunflower in response to day and night a tropic movement even thoigh no growth is involved

Answer 1

Motor cells are bases of the flower bud they change their shape and size by changing the amount of water in it which moves their faces towards sun. As there is involvement of cells it's called tropic movement.

I'm not pretty sure about this answer .

Answer 2

Beacause the sunflower respond to sun light, and we even know that plants does not have specialized tissues to send information, in plants as in animals thus they send information by electrical-chemical means, even the plants cell change their shape by changing the amount of water in them, resulting in the shrinking or swelling , and therefore it change shape and shows phototropism.

Even, beacause this movent of plant is called as ' Idependant of growth'.