Diversity in Living Organisms, Std-9

 

*Biodiversity

:- The term biodiversity or diversity has been derived from a  Latin word I.e "diversitas" meaning - Variation. 

:-> This term was coined by Walter G. 
    Rosen in 1986. 

:-> The variation among living organisms is
     called biodiversity. OR

:-> The appearance of different forms of life
     on the earth is called biodiversity. 

:-> No. of organisms on earth- 1.7 to 1.8 
    Million ( approximately). 

*Taxonomy 

:-> A biological science which deals with the

     Identification, nomenclature and                     classification of organisms is called                taxonomy. 

:- It provides names to each and every
   organisms. 

➤Nomenclature:- The process of giving
   standard name to the organisms is called
   nomenclature. 

:-> Organisms known all over the world by
   the same name. 

* Organisms have two names 1. Vernacular
   name, 2. Scientific name.
a. Vernacular Name:- The local name of
    organisms is called vernacular name.
:- It varries from one place to another.
:- It also creates confusion.
:-> e.g- A dog is called 'kutta' in Hindi,
    Kukur in Bangla and 'Naai' in Tamil etc.
b. Scientific Name:-  It is the standard
    name of organisms.
:-> It does not create confusion.
:-> An organism is known all over the world by single name I.e scientific name.
:-> e.g- Mango ( common name ) - Mangifera indica (scientific name).
* Binomial Nomenclature 
:- The process of providing standard name to an organism ( plant or animal) with two components ( generic & specific ) is called binomial nomenclature.
:- The naming system was given by - Carl Von Linnaeus. 
*Rules to write Scientific name of an organism. 
:- a. Generic name should starts with Capital letter and Specific name starts with small letter.
 b. Scientific names are written in Italics.    ( but In handwritten condition both part should be underlined separately ).
:- There are two institutions which give/ provide name to the organisms.
a. ICBN:- International Code of Botanical Nomenclature.
:- It gives name to the plants.
b. ICZN:- International Code of Zoological Nomenclature.
:- It gives name to the animals.
*Examples of Scientific name of organisms. 
 Common name.                  Scientific name
a. Lion                                  Panthera lio
b. Tiger                                Panthera tigris
c. Cat                                    Felis  catus
d. Cow                                  Bos indicus
e. Peacock                           Pavo cristus
f. Dog                                   Canis lupus
g. Neem                              Azadicta indica
h. Housefly                        Musca domestica
I. Tulsi                               Ocimum tenuiflorum
J. Buffalo                           Bubalus bubalis
k. Human                          Homo sapiens
l. Lotus                              Nelumbo nucifera
m. Ant                            Formicidae formicidae
n. Potato                         Solanum tuberosum
➤ Classification
:- The process of arranging/grouping organisms on the basis of their similarities and dissimilarities is called  classification.
:- This term was proposed by Linnaeus. 
* Importance of classification
a. It makes easy to study a wide variety of organisms.
b. It helps us to understand the relationship
  between different groups of organisms.
c. It helps us in exploring the diversity of life forms.
* Hierarchy of classification
:- A system of arrangement and framework for classification in which different taxonomic categories are placed logically is known as  hierarchy of classification.
:- It is as follows-
   Kingdom
                  Phylum
                              Class
                                      Order
                                               Family
                                                         Genus
                                                                   Species
:- When we move buttom to top similarity decreases and vice-versa.

* Different Kingdom Classification

1. Two Kingdom Classification

:- Proposed by - Carl Von Linnaeus in 1758.
:- He classified organisms into two groups I.e Plants & Animals, On the basis of Procuring food and Movement ( fixed or stationary ).
:- He saw that plants were stationary and
 trap sunlight to make their food & some plants even grow indefinitely whereas animals were  moving, eat plants or animals as food and stop growing after attaining a certain size.

2. Three Kingdom Classification
:- Proposed by - E. H. Haeckel in 1866.
:- He added third kingdom I.e Protista for Unicellular organisms.
:- He arranged kingdoms in following ways
     Kingdom Plantae
                          Kingdom Animalia
                                                Kingdom Protista.

3. Five Kingdom Classification
:- Proposed by - Robert H. Whittaker in 1959
:- Basis of classification were :
 a. The prokaryotic versus eukaryotic structure of cells, or whether the cells have a cell wall or not.
  b. The unicellular versus multicellular or multinucleate organisation, and
 c. The three different modes of nutrition: Photosynthesis ( plants), Absorption (fungi), and Ingestion ( animals ).  OR we can say in easy way 1. Cell structure
                  2. Mode of nutrition &
                  3. Body Organisation.
:- He arranged kingdoms in the  following ways :-
 * Kingdom Monera
            Kingdom Protista
                            Kingdom Fungi
                                     Kingdom Plantae
                                            Kingdom Animalia.
 
Note:- In 1977 Carl Woese  further divided kingdom Monera into Archaebacteria ( or Archaea ) & Eubacteria.     

 1. Kingdom Monera
:- These organisms are oldest, simplest and numerous microorganisms.

Features:-
1. These are prokaryotes. They do not have a defined nucleus.
2. They are mostly unicellular, but may be in the form of colonies of independent cells.
3. Some of them have cell walls while some do not.
4. Mode of nutrition :- Autotrophic  Or Heterotrophic.
5. They are usually non- motile but some may  have  flagella for movement.
6. Mode of reproduction:- Asexual ( By fission ).
E.g. Bacteria, Blue green algae or cynobacteria, Anabaena etc.

 2. Kingdom Protista               


Features:-

1. They are first Eukaryotes.                             

2. They have complex membranous organelles.

3. They are unicellular. 

4. Habitat :- Aquatic ( Fresh &  marine )

5. Some of these organisms use appendages as hair like cilia or whip like flagella for moving around. 

6. Mode of nutrition :- Autotrophic or Heterotrophic. 

E.g. Paramecium, Amoeba, Euglena, Diatom etc. 

3. Kingdom Fungi

Features :- 

1. They are multicellular eukaryotes. 

2. Habitat:- Dark, moist places.  

3. Mode of nutrition - Heterotrophic ( Saprophytic ). 

4. They are non- motile. 

5. Mode of reproduction:- mostly asexual or however sexual. 

E.g. Yeast, Mushroom, Penicillium and Aspergilus etc. 

:- They show mutual relationship with blue green algae, such relationship are called symbiotic. And these symbiotic life forms are called Lichens. 

Note :- Lichens:- slow growing large coloured patches on the bark of the tree). 

4. Kingdom Plantae 

Features :-

1. They are truly multicellular and Photosynthetic ( due to presence of a green pigment I.e Chlorophyll ). 

2. They have cell wall made up of true cellulose, enclosing cytoplasm with large     vacuole. 

3. They are non- motile. 

4. Mode of nutrition - Autotrophic.  

5. Mode of reproduction - Both Sexual & Asexual.
6. E.g. Mango,Peepal,Banyan tree, Tulsi etc. 

5. Kingdom Animalia

Features:-
1. They are  truly multicellular eukaryotes 
   without cell walls. 
2. They are motile /mobile. 
3. Mode of nutrition- Heterotrophic. 
4. Mode of reproduction- Sexual.  
5. E.g. Human, Cow, Dog,Lion etc.