The first step of an action potential, when the membrane potential of a neuron shifts from negative to positive due to inward movement of sodium ions, is referred to as .

The first step in action potential, where changes in transmembrane cell charges occur, is referred to as depolarization.

Explanation:

The relative charges in the intracellular and extracellular space are different, predominantly negative in the cytoplasm and positive in the extracellular space. These changes depend on the movement of ions -sodium and potassium- between the two spaces.

The opening of the sodium channels in the cell membrane allows this cation to enter the cell, making the relative charge inside the cell positive, which is called depolarization, first step of an action potential.

Learn more:

Action potential in the neuron link

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.

answer: c

explanation: