Photosynthesis in green plants is directly and indirectly dependent on so many plant structures. Explain briefly the role of the following structures in this process.

(a) Guard cells

(b) Cuticle

(c) Chlorophyll

(d) Stomata

(e) Xylem tissue in the leaf veins

(f) Phloem tissue in the leaf veins

(a) Guard cells — They are located in the leaf epidermis and pairs of guard cells surround and form stomatal pores. Guard cells use osmotic pressure to open and close stomata. And thus regulate the entry of carbon dioxide through the stomata.

(b) Cuticle — Cuticle is transparent and water proof to allow light to enter freely.

(c) Chlorophyll — Chlorophyll is vital for photosynthesis, which allows plants to absorb energy from light. Light energy is converted into chemical energy. With photosynthesis, chlorophyll absorbs energy and then transforms water and carbon dioxide into oxygen and carbohydrates.

(d) Stomata — The main function of Stomata is to let in carbon dioxide from the atmosphere for photosynthesis. Also most of the oxygen produced during photosynthesis diffuses out into the atmosphere through the stomata.

(e) Xylem tissue in the leaf Veins — Xylem cells mainly transport water and minerals from the roots to the leaves. Water is essential for photosynthesis to occur. Water is taken up by the roots from the soil, sent up through the stem and finally brought to the leaves (site of photosynthesis) through the xylem tissue. The water is then distributed in the mesophyll tissue.

(f) Phloem tissue in the leaf veins — The Pholem is composed of still living cells. Prepared food is transported from leaves to all parts of the plant by the phloem tissue. The glucose is converted into insoluble starch and later into soluble sugar sucrose, which is transported in solution through the phloem in the veins of the leaf and down through the phloem of the stem.