What will happen after the treatment of host cell with divalent cation ?

Change in permeability of DNA . Efficiency with which DNA enters the bacterium is increased. Change in permeability of host . Efficiency with which DNA enters the bacterium is decreased.

Efficiency with which DNA enters the bacterium is increased.

Host is made competent by treating them with specific concentration of a divalent cation such as calcium, which increases the efficiency with which DNA enters the bacterium through the creation of pores in its cell wall or cell membrane.