C) As hydrilla is aquatic in nature, the roots do not have to search for water, and there is no need for xylem to absorb water because the plant is surrounded by water.
Cold air creates high pressure low pressure is created by hot/warm air La Nina creates cooler temperature then el nino
1. The cell wall has lignin (hard substance): to prevent the xylem vessel from collapsing and withstand high pressure.
2. The absence of protoplasm (nucleus + cytoplasm) and cross wall: to allow water to move through the lumen easily.
Hope it helped!
