Statement I :  The  classification systems keeps on evolving depending on the improvement in our understanding of characteristics and evolutionary relationships.

Statement II : Though classification systems for the living organisms have  undergone several changes over the time, plant and animal kingdoms have been a constant under all different systems.

In the light of the above statements choose the most appropriate answer from the options given below.

 Classification systems for the living organisms are dynamic, they have undergone several changes over the time.  This happens because the criteria for classification changes with improvement in our understanding of characteristics and evolutionary relationships. Attempts are being made to evolve a classification system which reflects not only the morphological, physiological and reproductive similarities, but is also phylogenetic, i.e., is based on  evolutionary relationships.

In spite of all these changes, plant and animal kingdoms have been a constant under all different systems, however the understanding of what groups/organisms be included under these kingdoms have been changing;