Sam observed a slide containing the lower epidermis of a leaf under a microscope. A number of tiny openings between the epidermal cells were present as shown below in the diagram:

(a) What are these tiny openings called?

(b) Name the cells that regulate the opening and closing of the structures.

(c) Which ion is responsible for the opening and closing of the openings?

Why is Adrenaline called "The Emergency Hormone"?

Mention the significance of the following minerals:

(a) Iodine in our food.

(b) Magnesium for green plants.

State two objectives of Swachh Bharat Abhiyan.