Question

describe about hydrilla plant

Answer 1

Hydrilla is a genus of aquatic plant, usually treated as containing just one species, Hydrilla verticillata, though some botanists divide it into several species

Answer 2

Hydrilla like other hydrophytes is a submerged water plant and breathes underwater.So it is easy to see the oxygen being given out in water( in the form of bubbles) and can be collected and tested by the downward displacement of water.