The living organisms on earth can be classified as either prokaryotes or eukaryotes.
Evidence suggest that prokaryotic cells were formed during the primordial cells so they are considered the primitive cells. They lack the cellular organization due to the absence of the cellular organelles.
These cells modified themselves and formed the first cellular organelles and formed the eukaryotes. These eukaryotes posses the organelles. the nucleus of which is used to distinguish the eukaryotes from the prokaryotes.
Because if a scientists hypothesis is incorrect other scientists can adjust the experiment to make the hypothesis true or to prove it is truely incorrect.
