Which of the following membrane ion channels open and close in response to changes in the membrane potential?

voltage-gated channels

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

the atomic mass is the bottom number on the element.

-steel jelly

voltage-gated channels

Explanation:

voltage-gated Ion channels: They are proteins of multi-subunit complexes that reacts with confrontations changes that occurs in the members potential which results in the opening and closing of the pore. They mainly help to generate electrical signals within the cell membrane. The locations of the voltage-gated ion channels includes in the cell body of the neurons, on the dendrites, on the axon hillock, on the node of Ranvier, etc. Majorly, when ion channels open, it is a form of response to stimuli.