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www.GOALias.blogspot.comSimilarly, when we sweat, it helps to coolour body.11.3 TRANSPORTOF SUBSTANCESINPLANTSIn Chapter 1 you learnt that plants takewater and mineral nutrients from the soilthrough the roots and transport it to theleaves. The leaves prepare food for theplant, using water and carbon dioxideduring photosynthesis. You also learnt inChapter 10 that food is the source ofenergy and every cell of an organism getsenergy by the breakdown of glucose. Thecells use this energy to carry out vitalactivities of life. Therefore food must bemade available to every cell of anorganism. Have you ever wondered howwater and nutrients absorbed by theroot are transported to the leaves? Howis the food prepared by the leaves carriedto the parts which cannot make food?Transport of water andmineralsPlants absorb water and minerals bythe roots. The roots have root hair.The root hair increase the surface areaof the root for the obsorption of waterand mineral nutrients dissolved inwater. The root hair is in contact withthe water present between the soilparticles [Fig. 11.7 (a)].Can you guess how water movesfrom the root to the leaves? What kindof transport system is present in plants?Boojho thinks that plantsmay have pipes to transportwater to the entire plant likewe have in our homes for thesupply of water.Root hair(b)Xylem vessels(a)Fig. 11.7 Transport of water and minerals in(a) a section of root, (b) a tree128SCIENCE