Semipermeable means only certain substances can pass through. I imagine you are talking about cell membranes which are semipermeable. This means vital things like oxygen and nutrients are able to pass through the membrane, while not allowing everything to enter the cell
I'm thinking true heres why lets say you have a bird and the bird eats worms.. and all the worms in the world are gone the bird will die and what ever animal ate that bird will die and what ever animal ate that bird will die and so on
my guess
It changes heritable traits and phenotypes