Question

A complete ring of bark was removed from a tree in spring. The tree continued to live through summer but a swelling appeared on the bark above the ring while the bark below shriveled up. Answer the questions given below :

(i) Account for the swelling in the bark above the ring.
(ii) Account for the shrinking of the bark below the ring.
(iii) Name the tissue that distributes food in plants.
(iv) Name the tissue that distributes water in plants.
(v) What is the role of a bark in a plant?

Answer 1

(i) The phloem has been removed in the part of the ring. The food prepared by leaves comes down through phloem, but since the phloem is cut off, the food gets collected in the upper part of the ring and hence the swelling appears.
(ii) The food prepared by leaves is not able to pass on downward as the phloem has been removed, resulted in the shrinking of the bark. 
(iii) Phloem.
(iv) Xylem.
(v) Bark protects the attack of fungi and insects, against loss of water by evaporation and against variation of external temperature and loss of water due to evaporation.