Answer:
Cell Wall: This is the rigid outermost layer of a plant cell. It makes the cell stiff -providing the cell with mechanical support - and giving it protection. Animal cells do not have cell walls. Cell Membrane: This is a protective layer that surrounds every cell and separates it from its external environment.
In physical science there are two types of "isolated systems"
1. Being a Physical System in which it is so far removed from other systems that it does not react with any of them.
2. Being a Thermodynamic System in which it is enclosed by rigid immovable walls of which neither mass nor energy can flow through.
I believe in this case although not stated that it would refer to a Thermodynamic System which would leave you with the only plausible answer as ENERGY AND MATTER CANNOT ENTER OR LEAVE.
None of the other answers make sense. Even if it were referring to Physical. Physical does not react with anything at all. An as you can see Thermodynamic does not allow for anything to pass through or leave.
Answer:
A
Synapse, also called neuronal junction, its carries of information through electric nerve impulses between two nerve cells (neuron) or between a neuron and a gland or muscle cell (effector).
