(a) How does carbon dioxide from the air enter the leaves of a plant to be used in photosynthesis?
(b) How does water from the soil reach the leaves of a plant to be used in photosynthesis?

(a) The carbon dioxide gas enters the leaves of the plants through the stomata present on the surface of the leaves.

(b) The water required by the plants for photosynthesis is absorbed through the roots of the plants from the soil by the process of osmosis. It is then transported upward through the xylem vessels to the leaves where it reaches the photosynthetic cells and is utilized in photosynthesis.