Question

D 4. Leakage of positive ions across the cell membrane occurs by: A. Active transport B. Osmosis C. Passive transport D. Diffusion​

Answer 1

From the given question the correct answer is:

B. Osmosis

Leakage of positive ions across the cell membrane occurs by Osmosis

• water moves across them by osmosis from a solution of lower solute concentration to one of higher solute concentration.

• Most biological membranes are more permeable to water than to ions or other solutes, and Animal cells swell or shrink when placed in hypotonic or hypertonic solutions, respectively.

Answer 2

Option B is correct

Osmosis

Osmosis is a biophysical process that occurs often in biological systems, in which semipermeable membranes separate cells in fluid compartments. The diffusion of a solvent through a semipermeable membrane is referred to as osmosis. The concentration difference of solutes in the solutions separated by the semipermeable membrane drives the solvent shift. Solutes, unlike solvents, cannot cross over this barrier. Water, the most common solvent in biological systems, migrates from the compartment with the lowest concentration of solutes to the compartment with the highest concentration. When the concentration of osmotic active molecules in the two compartments is equal, the net fluid flux stops.

As a result, water distribution is determined by osmosis rather than solute transfer.