Mention the contribution of scientists in the early classification.

(N/A) $\rightarrow$ Since the time of civilization,there have been many attempts to classify living organisms.
$\rightarrow$ Initially,classification was done instinctively,not using scientific criteria,but based on the need to use organisms for food,shelter,and clothing.
$\rightarrow$ Aristotle was the earliest to attempt a more scientific basis for classification.
$\rightarrow$ Aristotle used simple morphological characters to classify plants into trees,shrubs,and herbs.
$\rightarrow$ Aristotle divided animals into two groups: those which had red blood and those that did not.
$\rightarrow$ Linnaeus developed the $Two$ $Kingdom$ system of classification with $Plantae$ and $Animalia$,which included all plants and animals,respectively.
$\rightarrow$ This system was used until very recently.
$\rightarrow$ This system did not distinguish between eukaryotes and prokaryotes,unicellular and multicellular organisms,and photosynthetic (green algae) and non-photosynthetic (fungi) organisms.
$\rightarrow$ While the classification of organisms into plants and animals was easy to understand,a large number of organisms did not fall into either category; hence,the $Two$ $Kingdom$ classification was found inadequate.