Taxonomy: the techniques of describing,naming and classifying living organisms on the basis of similarities and dissimilarities
Prokaryote: prokaryotes were the earliest living organisms which are unicellular having a primitive nucleus i.e they don’t have a true nucleus
Virus: viruses are non cellular parasitic entities. They cannot live or reproduce outside of living cells since they lack machinery to do so by themselves. They range in size from 20nm to 250nm
