Diversity in the living world. mohanBio

1. Unit 1. Diversity in the living world Chapter 1. THE LIVING WORLD

2. BIOLOGY : - The word biology was taken from Greek. Bio means life, logy means study of. Therefore biology means study of life. The branch of science, which deals with the study of structure, function, habitat and economic importance of organism is called biology. Aristotle was considered as father of biology . Life : - The living activity shown by an organism from birth to death is called life.

3. Characteristics of living organism: - Growth : The living things exhibit internal growth or intersusception growth.

4. Reproduction: During the life span all living organism reproduce themselves. Some organisms reproduce asexually & some sexually.

5. Metabolism: The living organism have metabolism. The total sum of chemical reaction occurs in side the organism is called metabolism. It is classified into 2 types . Anabolism Catabolism

6. Anabolism: - It is the chemical reactions in which large molecules are builds from smaller components. These are constructive reactions. EX: photosynthesis

7. Catabolism: - It is the chemical reactions in which break down of large molecules in to smaller components . These are distructive reactions EX: Cellular respiration, in which glucose is broken down in to CO2 & H2O.

8. cellular organization: All living organism have cellular organization. The cell forms the structural and functional unit of life. The organisms having only one cell are called unicellular organisms. EX: amoeba, paramecium, euglena etc The organisms having millions of cells showing organ and organ systems are called multicellular organism. EX: All plants and animals. ’ Size: The livings organism have definite farm and size.

9. Consciousness: All living organisms show response to stimulus. They have interim relation with surrounding environment.

10. Biodiversity : Term used to refer to the number of varieties of plant and animals in region on earth . Need for classification : living organisms are classified into categories because that could be named, remembered, studied and understood.

11. Nomenclature: Binomial nomenclature was first introduced by Carolus Linnaeus . He published the book ‘ Systema Naturae ’. The scientific naming of an organism using two w ords is called Binomial nomenclature. Each scientific name has two components - Generic name + Species name. Rules for Nomenclature : Latinised names are used. First word is genus, second word is species name. Printed in italics; if handwritten then underline separately . First word starts with capital letter while species name written in small letter . Ex: Mangifera indica .( mango)

12. ICBN : International Code of Botanical Nomenclature (for giving scientific name to plants.) ICZN : International Code of Zoological Nomenclature (for giving scientific name to animals .) Taxonomy : Study of principles and procedures of classification. Systematics : It deals with classification of organisms based on their diversities and relationships among them. Term was proposed by Carlous Taxonomic Hierarchy : It is the arrangement of various taxa of classification Species → Genus → Family → Order → Class → Phylum (for animals) Division (for plants) →Kingdom

13. SPECIES : Group of individuals having fundamental similarities in characteristics and successful reproduction takes place among themselves form a species.  E.g: Panthera tigris,Panthera leo Solanum tuberosum , Solanum nigrum .

14. GENUS : It consists of a group of related species. Genera are aggregates of closely related species. E.g:Panthera leo ,P pardus (leopard) ,P tigris

15. FAMILY It has a group of related genera. E.g:family Solanaceae includes genera solanum(tomato,potato) , petunia & datura. Family Felidae includes genera panthera (lion, tiger , leopard) & Felis (cat)

16. ORDER: It is the group of families which include a few similar characters. E.g:order polynomial includes family solanaceae & convovulaceae . E.g : carnivora includes family felidae & cancidae (dog) .

17. CLASS : It includes all related orders having few similar characters. . E.g : class mammalia includes order Primata (monkey, gorilla,gibbon ) & carnivora . E.g:class Dicotyledonae includes order polymoniales & sapindales (mango)

18. PHYLUM or DIVISION: It includes related classes having few similar characters. E.g:phylum Chordata includes classes fish , amphibia , reptilia , aves & mammalia . Division angiospermae includes class dicotyledonae & monocotyledonae .

19. TAXONOMICAL AIDS: Taxonomic studies of various species of plants, animals and other organisms require correct classification and identification. Identification of organisms requires laboratory and field studies . The other taxonomical aids are, Herbarium Botanical Garden Museum Zoological Park

20. Herbarium is a store house of collected plant specimens that are dried, pressed and preserved on sheets. Museums have collections of preserved plant and animal specimens. Zoological Parks are the places where wild animals are kept in protected under human care. Key Key is another taxonomical aid used for identification of plants and animals based on the similarities and dissimilarities.