Assertion (A): The loss of excess water from the aerial parts of the plant in the form of water vapour is known as transpiration.

Reason (R) : Stomata of the leaf perform transpiration.

Name the cell that surrounds the stoma.

Assertion (A): If the plant part moves in the direction of gravity, it is called positive geotropism.

Reason (R) : Stem shows positive geotropism

There are 3 plants A, B and C. The flowers of 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 when fingers or any other solid object.

a) Name the phenomenon shown by the flowers of plant A and B.

b) Name one flower each which behaves like the flowers of plant A and B.

c) Name the phenomenon exhibited by the leaves of plant C.

d) Name a plant whose leaves behave like those of plant C.’

While conducting experiments to study the effects of various stimuli on the plants, it was observed that the roots of a plant X grow and bend towards two stimuli A and B but bend away from a third stimulus C. The stem of the plant X however bends away from stimulus A and B but bends towards the stimulus C. The stimulus B is known to act on the roots due to factors related with Earth. Keeping these points in mind, answer the following questions:

a) What could be stimulus A ?

b) Name the stimulus seen in B.

c) What could be stimulus C ?