State the role of a green house in growing plants.
Elements that have no role to play in plants have not been found to be present in plants.
Which of the following statements are correct? (i) Companion cells are present in phloem. (ii) Xylem transports water and minerals from roots to other parts of the plant. (iii) Vessels of xylem are present in all plants. (iv) Both xylem parenchyma and phloem parenchyma have nucleus.