Paper 3 · June 2017 · aeroponics and fermenter design
In aeroponics the roots of the crop are
Aheld in a closed chamber and sprayed with a mist of nutrient solution.
Bleft standing in a tank of aerated nutrient solution throughout growth.
Cplanted in a shallow layer of sterile soil fed by a drip line.
Danchored in a bed of gravel that is flooded and drained on a cycle.
Explanation
Aeroponics suspends the plant so that its roots hang free in an enclosed dark chamber, and a fine mist of nutrient solution is sprayed onto them at intervals. The roots therefore sit in air rather than in water, gravel or soil, which is what separates the technique from hydroponics and from ordinary soil culture.
Derived from ZIMSEC Biology Paper 3, Jun 2017, Q11