Question

Give merits & demerits of five kingdom system.

Answer 1

Merits

1) The complexity of cell structure, prokaryotic and eukaryotic.

2) The complexity of body structure or structural organization, unicellular and multicellular.

3) Mode of nutrition which is divergent in multicellular kingdoms- photoautotrophy in Plantae, absorptive heterotrophy in fungi and ingestive heterotrophy in animalia. Photoautotrophic nutrition is also called holophytic nutrition while ingestive heterotrophy is known as holozoic nutrition. Absorptive heterotrophy is saprobiotic (=saprophytic ) nutrition.

4) Ecological lifestyle like producers (Plantae), decomposers (fungi) and consumers (animalia).

5) Phylogenetic relationships.

Demerits

1) The kingdoms Monera and Protista include diverse, heterogeneous forms of life. In both the kingdoms, there are photosynthetic (autotrophic) as well as non-photosynthetic (heterotrophic) organisms. Both the kingdoms include organisms which have cells with cell wall as well as without cell wall.

2) Unicellular green algae like Volvox and Chlamydomonas have not been included under Protista because of their resemblance to other green algae.

3) Slime moulds differ totally from other members of Protista in their general organization.

4) Viruses have not been given proper place in this system of classification.

5) Multicellular lines have originated from protistans several times.