Question

Match the columns and choose the correct combination.

Answer 1

a) Relay pump theory was given by Godlewski. According to this theory, the ascent of sap takes place due to rhythmic change in the osmotic pressure of xylem parenchyma and medullary rays. This change in osmotic pressure provides the pumping action of water in an upward direction.

b) Transpiration cohesion theory was proposed by Dixon and Jolly. According to this theory, leaves lose water into the atmosphere by transpiration.

c) Mass flow theory was proposed by Ernst Munch. It explains the movement of sap through the phloem by bulk flow (mass flow) from sugar sources to sugar sinks.

d) Jagadish Chandra Bose proposed pulsation theory. According to this theory, living cells of the innermost layer of the cortex are in rhythmic pulsations. This pulsation provides the pumping action of water in an upward direction.