Question

what part of the plant permits it to watistan very dilute external medium without bursting

Answer 1

It is the cell wall that permits fungi, plant cells to withstand very dilute media without bursting. These cells when kept in a dilute medium take water due to osmosis, become swollen and exert pressure on the cell wall. Cell wall enables them to withstand this pressure as, it exert an equal pressure on cell, thus prevent bursting.