All organisms consist of structural units called cells; some contain a single cell (unicellular) and others contain many units (multicellular). Multicellular organisms are able to specialize cells to perform specific functions. Organisms have both internal and external macroscopic structures that allow for growth, survival, behavior, and reproduction.. All living things are made up of cells. In organisms, cells work together to form tissues and organs that are specialized for particular body functions.
Answer:
When the solutions (including inside and outside) were replaced by NaCl, the membrane potential changes from a negative value of -60 mV to a positive value of + 60 mV.
Explanation:
According to the Nernst equation the potential of the membrane for a two-compartment model of a cell for positive gradient of K⁺ ions is V = - 60 mVlogK'/K where K' = inside concentration of K⁺ ions and K = outside concentration of K⁺ ions. For a 10 fold excess of KCl in the inside compartment, K'/K = 10. So,
V = - 60 mVlogK'/K = - 60 mVlog10 = -60 mV.
For a negative gradient of Na ions is V = + 60 mVlogK'/K where K' = inside concentration of Na⁺ ions and K = outside concentration of Na⁺ ions. (Since the cell is selectively permeable to Na⁺ ions. So, Na ions to not flow out but in.)For a 10 fold excess of NaCl in the inside compartment, K'/K = 10. So,
V = + 60 mVlogK'/K = + 60 mVlog10 = +60 mV.
So, when the solutions (including inside and outside) were replaced by NaCl, the membrane potential changes from a negative value of -60 mV to a positive value of + 60 mV.
The answer to your question is B.
