Question

In Ganong's respirometer a respiratory substrate is kept and observed that the level of Hg in leveling tube is fall. The respiratory substrate should be a:-
(1) Groundnut seed
(2) Wheat seed
(3) Pieces of Opuntia stem
(4) Soyabean seed

Answer 1

Ganong’s respirometer designed to measure oxygen uptake orCO2 release. Germinating seeds have a high rate of respiration, thereforeoxygen in the apparatus is used up. Thislowers the air pressure inside the bulb raising the level of mercury.Falling the level of mercury indicates the absence of respiration. Thus, the
correct answer is (3) Pieces of Opuntia stem