2. BIOLOGICAL CLASSIFICATION
Biological classification has evolved from early morphological criteria adopted by Aristotle to a sophisticated five-kingdom classification proposed by Whittaker, which includes Monera, Protista, Fungi, Plantae, and Animalia. This classification considers various factors like cell structure, body organization, and evolutionary relationships. The chapter also briefly discusses acellular organisms like viruses and their unique characteristics.
Enroll to start learning
You've not yet enrolled in this course. Please enroll for free to listen to audio lessons, classroom podcasts and take practice test.
Sections
Navigate through the learning materials and practice exercises.
What we have learnt
- Classification of living organisms has evolved from a two-kingdom system to a five-kingdom system.
- Bacteria, which belong to the Kingdom Monera, exhibit extensive metabolic diversity and can be autotrophic or heterotrophic.
- Viruses are non-cellular entities and are considered obligate parasites, lacking the characteristics of living organisms.
Key Concepts
- -- Five Kingdom Classification
- A classification system proposed by Whittaker, categorizing life into Monera, Protista, Fungi, Plantae, and Animalia based on cell structure, body organization, and nutritional modes.
- -- Archaebacteria
- A group of bacteria living in extreme environments, characterized by unique cell wall structures which enable their survival.
- -- Eubacteria
- True bacteria that possess a rigid cell wall and include both harmful and beneficial species.
- -- Protista
- A kingdom that includes all single-celled eukaryotes, bridging the gap between plants, animals, and fungi.
- -- Fungi
- Heterotrophic organisms that can be saprophytic or parasitic, characterized by unique cell walls made of chitin.
- -- Viruses
- Infectious agents with a simple structure composed of nucleic acid and a protein coat, which require a host cell to replicate.
Additional Learning Materials
Supplementary resources to enhance your learning experience.