Which one of the following is the correct sequence of events that correlates to the sequence of events of a nerve impulse? 1. the membrane becomes depolarized 2. sodium channels open and sodium ions diffuse inward 3. the membrane becomes repolarized 4. potassium channels open and potassium ions diffuse outward while sodium is actively transported out of the cell

2, 1, 4, 3.

Explanation:

The cell membrane potential may be defined as difference in the electric gradient inside and outside of the cell. The ions are important to create the voltage difference.

The nerve impulse transmission occurs by its propagation. The cell is at the resting membrane potential. The opening of sodium ions causes the inward diffusion of the ions. This causes the membrane potential become more positive and the cell depolarize. Then potassium ions starts diffuse in the cell and sodium ions move out. This causes the repolarization of cell.

Thus, the correct sequence is  2, 1, 4, 3.

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.

i think it is dna, i'm not totally sure but i think it might be.