The aquifer which will be most effective in purifying polluted ground water is AN AQUIFER COMPOSED MAINLY OF SAND.
An aquifer refers to a zone of permeable rock strata which transmit ground water freely. An aquifer must be permeable and porous. Ground water can be extracted from an aquifer by using a water well.
An action potential will not occur unless the membrane potential AT THE VOLTAGE GATED SODIUM CHANNEL reaches a level called THRESHOLD.
An action potential refers to the change in the electrical potential which occurs as a result of the passage of impulses along the membrane of muscle cells or nerve cells. An action potential occurs when there is depolarization of the cell membrane to the threshold stage.
The answer to your question is C
Warm water holds less oxygen than cold water does.