question_answer 21)

How do auxins promote the growth of a tendril around a support?

Answer:

When the tip of tendrils touches a support, then the auxins present in its tip move to that side which is away from the support. Auxins promote growth. So, due to more auxins in it, the side of tendril away from the support grows faster and becomes longer than the side which is in contact with the support and makes the tendril curve and bend towards the support. This curving tendril can then encircle the support and ling around it.