Why is the closing of a Dandelion flower at dusk (when it gets dark) not a tropism?

Why is the folding up of the leaves of a sensitive plant on touching with a finger not a tropism?

The closing of the flowers of some plants after sunset illustrates

When the leaves of a sensitive plant are touched with a finger, they fold up and when light fades at dusk, the petaks of a dandelion flower close. (a) State one way in which the above two processes are similar. (b) State two ways in which the above two processes differ.

Opening and closing of Crocus/Tulip flower is

Why the colour of heart wood is dark ?

Why does a wire get heated when it is bent back and forth ?

There are three plants A,B and C. the flowers of plant A open their petals in bright light during the day but close them when it gets dark at night. On the other hand, the flowers of plant B open their petals at night but close them during the day when there is bright light. The leaves of plant C fold up and droop when touched with fingers or any other solid object. (a) Name the phenomenon show by the flowers of (i) plant A, and (ii) plant B. (b) Name one flower each which behaves like the flower of (i) plant A, and (ii) plant B. (c) Name the phenoenon exhibited by the leaves of plant C. (e) Which plant/plants exhibit the phenomeon based on growth movements?

(a) What does a Mimosa pudica plant do in response to touch? What is this phenomenon known as? (b) What happens to the dandelion flower (i) during daytime, and (ii) at night? What is this phenomenon known as?