What process or event was required for plate tectonics to begin on earth ?

The tectonic plates appeared when the earth began to cool, where the water flooded the earth. The earth that was submerged originated the tectonic plates.

Explanation:

Plate tectonics are large semirigid rock blocks that make up the earth's crust. The Earth is divided into fourteen main tectonic plates, which move slowly and continuously over the mantle, and can approach or move away from each other.  The movement of the plates results in the formation of mountains, oceanic pits, volcanic activities, earthquakes and tsunamis.

The formation of tectonic plates was a result of the cooling and flooding of the earth. When the earth began to cool, where water flooded the earth. The submerged earth originated the tectonic plates.

it has to be understood that the sea water contains a huge amount of sodium and chlorine ions and if they enter the cell of the atlantic cod fish, the cell will shrivel and the fish will die. to avoid such a condition, the fish uses active transport for the purpose of removing the ions against the gradient.

explanation:

the atlantic cod is not a maritime osmoconformer. its native application of salts is less than that of the seawater it lives in. it is continually falling water from the gills to the ocean via osmosis.

countering that, the fish is going to be swallowing seawater. but since its internal collection of salts is lower than seawater, the fish will want to go free of excess salt, and since that's going upon a gradient, then active transport, requiring energy, must be used to pump out the salt. much marine fish use the organs to filter out the salt and these fish discharge very straight urine.