a] What is tropism?
b] How do auxins promote the growth of a tendril around a support?

Explanation

a] The plants adapt themselves according to the change in the environment, the action of plants according to the factors around it is known as tropisms. Tropisms is the growth of plants in response to stimulus as an example light, gravity, water and touch-types of tropisms are phototropism, gravitropism, hydrotropism and thigmotropism
b] The auxins is a plant hormone, it is present in the tendril of the plants. When tendril comes in contact with anything it grows faster towards the thing due to thigmotropism it is that.s why tendri gets coiled around the support.