Question

Match the theories given with the names of scientists. Choose the answer which gives the correct combination of the alphabets.

Names of theories	Names of scientists
A. Relay pump theory	p. Schleiden
B. Cohesion tension theory	q. Sir J.C. Bose
C. Mass flow theory	r. Godlewski
D. Pulsation theory	s. Dixon and Jolly
	t. Ernst Munch

• A. A- q, B- p, C- t, D- r
• B. A- r, B- q, C- t, D- q
• C. A- s, B- r, C- p, D- q
• D. A- r, B- s, C- t, D- q

Answer 1

The correct option is D A- r, B- s, C- t, D- q

According to Godlewski, rhythmic change in the water potential of xylem parenchyma and medullary ray are responsible for the pumping action of water in an upward direction in ascend of sap. This is called as relay pump theory.

According to Dixon and Jolly, due to intermolecular attraction, water flows in an upward direction against the gravity through the xylem of plants. This is called as cohesion tension theory.

According to Ernst Munch, movement of sap through the phloem occurs by mass flow from sugar rich area to sugar deprived area. This is called as mass flow theory.

According to Sir J.C. Bose, the conduction of water upwards through the xylem vessel is a result of pulsation and turgor pressure which produces contractive and expulsive movements. This is called as pulsation theory.

Thus, the correct answer is option D.