Class 11th - Biological classification
- 2. Identifying organism and placing them into groups according to their significant features and their relationship with other organism. • Linnaeus divided the iving organism into two kingdom i.e. plantae and animalia. • Each Kingdom was divided into phyla and divisions.Each phylum or division is divided into classes . • A class is subdivided into orders. • And order is divided into small groups called families. • Each family comprises of many genera and each genus were included into one or more species. 1. Plantae: Food is stored in form of starch. Plant cell is bounded by made up of cellulose hemicellulose etc. Chloroplast is used for photosynthesis. Dracula single and large and if player is called topoplast. There is no locomotion in plants . Irritability and sensitivity is also seen in plants example is Mimosa pudica. Growth is present. Reproduction is done by vegetative method , sexual method and asexual method. 2. Animalia: In this food is stored in form of glycogen. There is no cell wall. Vacuoles are many and small. There is no chloroplast. Animal show both locomotion and movement. They also show irritability and sensitivity. Reproduction is done by sexual and asexual method.
- 3. • It was given by Ernest hacklae he created a third Kingdom Protista which include bacteria algae fungi and protozoa. • So according to Earnest hacklae there are three kingdoms that are Plantae, Protista and animalia. • Its drawbacks are: 1. Acellular and multicellular organism were placed together in Protista. 2. Bacteria and fungi were grouped with unrelated organisms. • organism can't be easily placed either in plant and or in animal kingdom because they possess dual characters of both kingdoms. • example euglena: it has two characteristics --- it can respire like plants with photosynthesis. It can do locomotion like animals • Fungi cannot do locomotion like plants but the food is stored in form of starch. • Some of the organisms like virus cannot be place in in either of of these two kingdoms because they show both living and nonliving characteristics. Living like characteristics are : they can respire they can multiply they have enzymes they have genetic material life DNA and RNA . Non living characteristics are they have no Cellular organisation they may not respire in absence of oxygen they cannot digest food they can be crystallized.
- 4. R.H. Whittaker classified the organism into five kingdom classification :- 1.Monera 2.Protista 3.Fungi 4.Plantae 5.Animalia 1. No of cells:- • On basis of number of cell organisms are of two types • Unicellular:-If organism is made by a single cell e.g. Bacteria • Multicellular:-If organism is made by more than one cell . E.g. from sponges to higher organisms. 2. Nature of cell :- two types prokaryotes and eukaryotes. • Prokaryotes:- No well defined nucleus e.g. Monera • Eukaryotes :- well defined nucleus e.g. like Animals 3. Mode of nutrition:- • Autotrophic e.g. Plants • Hetrotrophic e.g. Animals , Fungi etc. 4. Evolution :- characters changes with time i.e. adaptations with time . Unicellular multicellular
- 5. • This system seems more natural and indicates gradual evolution of early organisms into plants and animals. • Kingdom animalia has become more homogeneous with the exclusion of protozoa. • Kingdom plantae has become more coherent after exclusion of bacteria, fungi and some unicellular algal forms. • Some organisms like euglena showing mixotrophic mode of nutritioncould be placed either in plant or animal kingdom easily . • The creation of kingdom Protista including all unicellular eukaryotes, irrespective of the mode of nutrition , has resolved this problem . • Kingdom Monera and Protista still retain heterogenosity , as both hetertroph and autotroph organisms with or without cell wall are included in both these kingdoms. • The slime moulds was different from other Protista with which they have been combined. • Unicellular algae like chlamydomonas are placed in kingdom Plantae rather than Protista. • Placing algae in three kingdoms seems to be unrealistic. • Viruses do not find any place. • Red and brown algae are not related to other members of kingdom Plantae.