Question

Component of living cell affected by pollutant SO${}_2$ is

• A. Nucleus
• B. All cell membrane system
• C. Cell wall
• D. None of the above

Answer 1

The correct option is B All cell membrane system

In SO${}_2$ pollution, plants show initial reduction of photosynthesis and increased respiration. The gas reduces stomatal opening and thus causes general water stress in plants. SO${}_2$ replaces oxygen in cellular materials and changes their nature. It affects structural proteins in the cell membrane and thus changes the membrane permeability. High concentration of the gas causes accumulation of sulphydril and decrease of sulphides in plants. SO${}_2$ interferes with amino acid metabolism and reduces the synthesis of proteins and enzymes. It stimulates the oxidation of PGA and increases the pentose phosphate cycle activity. It reduces the level of keto acids, ATP, sucrose and glutamate in plants and increases the level of glucose, fructose and glycolate. It inactivates many enzymes either by breaking their S-S bonds or by changing their stereo structure. In lichens , the gas induces photooxidation in the phycobiont part.

Therefore, the correct answer is option B.