Question

According to the mass flow hypothesis movements of the solutes occur from

• A. Sink to source
• B. Sink to sink
• C. Source to source
• D. Source to sink

Answer 1

The correct option is D Source to sink

All plant cells do not carry out photosynthesis. Only green leaf cells carry out photosynthesis. Photosynthesizing cells serve as source of assimilates or sugars. According to Munch mass flow hypothesis, photosynthates are translocated from source to sink through phloem sieve tubes.

Source is that region of plant, where sugars are present in larger concentration, example- green leaves, where they are produced as a result of photosynthesis. Those parts serve as sink, which do not synthesize sugars but utilize or store sugars.