Final answer:
The direction of the chemical force and electrical force on an anion at a resting membrane potential of -70 mV, with the anion's equilibrium potential at -40 mV, are opposite to each other. The electrical force drives the anion into the cell due to the negatively charged interior, whereas the chemical force drives it out based on the concentration gradient.
Step-by-step explanation:
The question relates to the direction of chemical and electrical forces acting on an anion at a resting membrane potential of -70 mV, given that the anion's equilibrium potential is -40 mV. When a neuron is at rest, the inside of the cell has a negative charge compared to the outside. At the resting membrane potential (-70 mV), which is more negative than the equilibrium potential of the anion (-40 mV), the electrical force would drive the anion into the cell due to the attractive force between opposite charges.
Meanwhile, the chemical force, driven by the concentration gradient, typically aims to move ions from areas of high concentration to areas of lower concentration. Assuming the anion is more concentrated outside the cell than inside, the chemical force would drive the anion out of the cell towards an area of lower concentration. Hence, the correct answer would be that the electrical force drives the anion into the cell, while the chemical force drives it out.