Question

Which of the following statements is false with regard to gas vacuoles?

• A. Gas vacuoles are found in many aquatic bacteria like cyanobacteria.
• B. Gas vacuoles are protein-bound structures containing air that allow the bacteria to control their buoyancy.
• C. Gas vacuoles are protein-bound structures containing water that allow the bacteria to control their buoyancy.
• D. The inflation and deflation of the gas vesicles is coordinated with the light.

Answer 1

The correct option is C Gas vacuoles are protein-bound structures containing water that allow the bacteria to control their buoyancy.

Gas vacuoles are aggregates of hollow cylindrical structures called gas vesicles. They are located inside some bacteria. A membrane that is permeable to gas bound each gas vesicle. The inflation and deflation of the vesicles provide buoyancy, allowing the bacterium to float at the desired depth in the water. Bacteria that are known as cyanobacteria contain gas vacuoles. Cyanobacteria, which used to be called blue-green algae, live in water and manufacture their own food from the photosynthetic energy of sunlight. Studies have demonstrated that the inflation and deflation of the gas vesicles are coordinated with the light. The buoyancy provided by the gas vacuoles enables the bacteria to float near the surface during the day to take advantage of the presence of sunlight for the manufacture of food, and to sink deeper at night to harvest nutrients that have sunk down into the water.