Question

In five kingdom system, the main basis of classification : -
A. Structural of nucleus
B. Nutrition
C. Structure of cell wall
D. Asexual reproduction

Answer 1

Five kingdom classification: It is a mode of classification in which living beings have been distributed into five kingdoms. It was proposed by American taxonomist R.H. Whittaker in 1969. It excludes viruses from living beings. He retained the subdivisions of the old two-kingdom classification. They have been redistributed into five-kingdoms to make them represent phylogeny of different life styles.

Complete answer:
The five kingdoms are monera, protista, fungi, plantae and animalia.
Whittaker (1969) used three criteria for delimiting the five kingdoms-complexity of cell structure, complexity of body structure and mode of nutrition. He also discussed their ecological life styles and phylogenetic relationships.
Mode of nutrition: Two main types are :
A. Autotrophy : Manufacture of organic food from inorganic raw materials. Energy is required for this. In chemosynthesis, chemical energy is employed for synthesis of food. Photosynthesis, light energy, is used for the manufacture of food. Photosynthesis is more important as it brings in energy from outside the biosphere. Photosynthesis performed by photoautotrophic bacteria is anoxygenic, without liberation of oxygen. Blue-green algae and eukaryotic photoautotrophs perform oxygenic photosynthesis which liberates oxygen. It is also called holophytic nutrition.
B. Heterotrophs: It is a mode of nutrition in which ready-made organic food is obtained from outside. Ingestive heterotroph: solid or particulate food is taken in. It is also called phagotrophy or holozoic nutrition. Absorptive heterotrophy: soluble food is taken from outside. It is of two types, saprobic and parasitic. In parasitic nutrition, the food is absorbed directly from another living organism or host. In saprobic or saprotrophic nutrition, food is obtained from organic remains. Absorption is made possible by solubilisation of organic remains through secretion of digestive enzymes.

Hence, the Correct answer is option B.

Note:
Multicellular heterotrophic motile organisms are retained in kingdom animalia. Multicellular photosynthetic eukaryotic organisms are kept in kingdom plantae or metaphyta. Multicellular Non-vascular, achlorophyllous, heterotrophic eukaryotic fungi have been separated into their own kingdom. Unicellular plants, unicellular fungi and protozoans are separated in the kingdom protista. Prokaryotic organisms consisting of bacteria and multicellular blue-green algae are transferred into a new kingdom of monera. However, there is some ambiguity about protista as well as monera.