Question : (a)Transport of food in plants require living tissues and energy. Justify the statement .(b)Namethe componentof food translocated by livingtissues.

Question : (a)Transport of food in plants require living tissues and e

1.	Question : (a)Transport of food in plants require living tissues and energy. Justify the statement .(b)Namethe componentof food translocated by livingtissues.
Answer» Solution :(a) Food materials are translocated fromthe region of theirmanufacture or storage, to the region of their utilisation via a complex tissue known as phloem. Phloem comprises of four types of tracheary elements - sieve tubes, COMPANION cell, phloem parenchyma and phloem fibres. Only phloem fibres are dead cells while rest are living. Food moves into sieve tubes which are the CONDUCTING channels of phloem. They are elongated tubular channels formed by end to end union of numerous sieve tubeelements. The end walls of sieve tubes have PORES and are called as sieve plates. Their functioning is controlled by adjacentnucleated companion cells as it produces the force required for translocation. The direction of translocation can be downward, upward or both. (b)The bulk of the translocation nutrients consist of SOLUBLE carbohydrate i.e, SUCROSE. Amino acids, organic acids, hormones and other organic solutes are also translocated bysieve tubes.