Question

The plasma membrane is selectively permeable what will happen if its loses its its permeability

Answer 1

*it would become infected with the bacteria and viruses in your body alot faster, would also absorb other cells due to there being nothing from stopping outside objects from entering its body. 
*in other words, nothing good

Hope It helps You Thanks =)

Answer 2

Hey friend,
Here is your answer:

If plasma membrane is selectively permeable membrane, and if its loses its permeability,
• unwanted matter will enter the cell and destroy the cell.
• the cell may easily allow viruses and bacteria and make the organism sick.

Hope it helps u.