Question

The interconversion of sugar and starch is dependent on pH changes in the guard cells were demonstrated by

• A. Levitt
• B. Lloyd
• C. Sayre
• D. Steward

Answer 1

The correct option is C Sayre

Starch Sugar Inter-conversion theory was given by the Sayre (1926) and supported by the Scarth (1932). This theory states that stomata open in neutral or alkaline pH, which prevails during day time due to constant removal of carbon dioxide by photosynthesis. Stomata remain closed during the night when there is no photosynthesis and due to the accumulation of carbon dioxide, carbonic acid is formed that causes the pH to be acidic. Thus, the stomatal movement is regulated by pH due to inter-conversion of starch and sugar.

So, the correct answer is 'Sayre'