Question

Mass Flow Hypothesis of Munch was elaborated by
A. Mason and Maskell
B. De Vries
C. Crafts
D. None of the Above

Answer 1

The other name of Mass Flow Hypothesis is Pressure Flow Hypothesis. It describes the processes of conducting saps through phloem. From adjacent xylem tissues, it draws water in the cells, as the highly concentrated sugar in the cells create a diffusion gradient from leaves. In this way, a type of hydrostatic pressure is created in phloem.

Complete answer:
1. Mason and Maskell are well-known in the domain of Botany for their Diffusion Analogue theory where they researched with cotton plants. This is mainly related with the translocation flow as happened in phloem.
2. De Vries' theory was related with the evolution. According to him, mutations or discontinued variations are nothing but some raw materials of evolution.
3. Alden Crafts worked to clarify many challenging and difficult problems in order to understand the translocation as happened with phloem.
4. German Physiologist Ernst Munch in 1930 first told about Mass Flow Hypothesis in detail which he observed in phloem tissues as it delivers solutes out of the elements of sieve-tube and produce opposite effects. So, we can say that the option ‘None of the Above’ will be correct here for this question.

Hence the correct answer is option ‘D’.

Note: If we summarize Munch’s hypothesis, we can see his research-based prediction that the pressure differential between a source and a sink is responsible for increasing the distance between them. In brief, we can find two valuable points in Munch’s hypothesis. They are the mechanism of translocation by mass flow from the sources to sink and the osmotic mechanism of pressure flow.