The correct answer is B.
The cell membrane is a two-layer lipid membrane that surrounds and protects the cell. It allows only certain molecules to enter and leave the cell, that's why we call it semi-permeable. The membrane is permeable only for small,uncharged molecules which enter and leave in the process of osmosis. All other types of molecules require a special transport protein or a channel in order to be transported trough the cell membrane.
Has an iron ion (and it's called haem btw)
If a neuron is exposed to tetrodotoxin ,sodium ions will be unable to cause the action potential,therefore being blocked from passing any impulses or receiving them...
Question 1: A.)
Question 2: i would say A.)
Question 3: C.)
Question 4: B.)
Question 5: A.)
Question 6: B.)
Hope this heslp
