Question

how auxin promote growth of the tendril around support?
Please explain in an easy word or if you can write in Hinglish it would be much appreciated

Answer 1

you watch a plant develop over time, you will notice that it grows up, out, and down. The stem grows up, making the plant taller. The leaves grow outward, reaching toward sunlight. The roots grow downward, absorbing nutrients and providing stability underground.
But what signals the parts of a plant to grow like this? Just like your body, plants have a variety of hormones, and auxins are a specific group of hormones that make plant cells grow. Auxins are not only critical to plant growth, but they were also the first class of plant hormones to be discovered. A Dutch graduate student named Frits Went first described auxins in 1926 and chose the name auxin from the Greek word 'auxien,' which means 'to grow.'

Answer 2

Auxin increase in concentration in the part of the tendril which is away from the support. This results in increased cell division in that part. The part which is nearer to the support has lesser rate of cell division. As a result, the external part of the tendril grows more than the internal part and the tendril coils around the support. When the tendril touches a support, auxin moves to the opposite side causing more growth on that side. This makes the tendril twine around the support.