Diversity - Classify organisms into five kingdoms using cellular organisation and mode of nutrition
Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
The Five Kingdom classification was proposed by Robert Whittaker in 1969 based on cell structure, mode of nutrition, and body organization.
Kingdom Monera: Consists of unicellular prokaryotic organisms. They do not have a defined nucleus or organelles. Nutrition can be autotrophic or heterotrophic. Examples: Bacteria, Blue-green algae ().
Kingdom Protista: Includes unicellular eukaryotic organisms. They possess a well-defined nucleus and membrane-bound organelles. Some use appendages like cilia or flagella for movement. Examples: , , .
Kingdom Fungi: Multicellular (except yeast), eukaryotic, heterotrophic organisms. They are saprophytes, absorbing nutrients from decaying organic matter. Their cell walls are made of a tough complex sugar called chitin.
Kingdom Plantae: Multicellular eukaryotes with cell walls made of cellulose. They are autotrophs and use chlorophyll for photosynthesis. Examples: Mosses, Ferns, Flowering plants.
Kingdom Animalia: Multicellular eukaryotes without cell walls. They are heterotrophs with a holozoic mode of nutrition (ingesting food). Examples: Insects, Fish, Humans.
Basis of Classification: (1) Cellular Organization (Prokaryotic vs. Eukaryotic), (2) Body Organization (Unicellular vs. Multicellular), and (3) Mode of Nutrition (Autotrophic vs. Heterotrophic).
📐Formulae
💡Examples
Problem 1:
An organism is eukaryotic, multicellular, heterotrophic, and has a cell wall made of chitin. To which kingdom does it belong?
Solution:
Kingdom Fungi
Explanation:
The presence of a eukaryotic cell structure and multicellularity excludes Monera and Protista. The heterotrophic mode of nutrition and a cell wall made specifically of chitin are the defining characteristics of Kingdom Fungi.
Problem 2:
Differentiate between Monera and Protista based on their cellular organization.
Solution:
Monera are Prokaryotic ( ); Protista are Eukaryotic ( ).
Explanation:
While both kingdoms primarily contain unicellular organisms, the fundamental difference lies in the complexity of the cell. Monerans lack membrane-bound organelles, whereas Protists possess them.
Problem 3:
Why are Blue-green algae placed in Kingdom Monera and not in Kingdom Plantae?
Solution:
Because they are Prokaryotic.
Explanation:
Even though Blue-green algae (Cyanobacteria) perform photosynthesis like plants, their cellular structure is prokaryotic (lacking a nuclear membrane), which is the primary criterion for Kingdom Monera.