By going through these CBSE Class 11 Biology Notes Chapter 2 Biological Classification, students can recall all the concepts quickly.

Biological Classification Notes Class 11 Biology Chapter 2

Aristotle was the first to propose the biological classification of plants and animals on the basis of simple morphological characters.

Later on, Linnaeus classified all living organisms into two kingdoms:

  1. Plantae and
  2. Animalia.

An elaborate five kingdom classification was proposed by Whittaker.

These include Monera, Protista, Fungi, Plantae, and Animalia
1. Kingdom Monera includes all types of bacteria etc. These organisms show the most extensive metabolic, diversity. In the mode of nutrition, they may be autotrophic or heterotrophic.

2. Kingdom Protista includes all single-celled eukaryotes. These include Chrysophytes, Dinoflagellates, Eaglenoids, Slime-moulds, and Protozoans. They reproduce both sexually and asexually and have defined nucleus and other membrane-bound organelles.

3. Kingdom Fungi show a great diversity in structures and habitat. They reproduce both sexually and asexually. Most Fungi are saprophytic.

4. Plantae includes all eukaryotic chlorophyll-containing organisms. The life cycle of plants exhibit alternation of generations-gametophytic and sporophytic generations.

5. Kingdom Animalia includes heterotrophic eukaryotic, multicellular organisms lacking a cell wall. They’ll reproduce by sexual mode

→ Saprophytes Organisms that absorb organic matter from dead substrates are called saprophytes.

→ Parasites Organisms that depend on living plants and animals are called parasites.

→ Plasmogamy The fusion of protoplasms between two motile or non-motile gametes.

→ Karyogamy The fusion of two nuclei.

→ Alternation of generation The lengths of the haploid and diploid phases and whether these phases are free-living or dependent on others. Such a phenomenon is called alternation of generation.

→ Viroids Micro-organisms smaller than viruses that lack the protein coat are termed viroids.