Living World PDF

LIVING WORLD 1. The number of species that are known and described range between 1.7-1.8 million. //3 2. there is a need to standardise the naming of living organisms such that a particular organism is known by the same name all over the world. This process is called nomenclature. //4 3. nomenclatur...

LIVING WORLD 1. The number of species that are known and described range between 1.7-1.8 million. //3 2. there is a need to standardise the naming of living organisms such that a particular organism is known by the same name all over the world. This process is called nomenclature. //4 3. nomenclature or naming is only possible when the organism is described correctly and we know to what organism the name is attached to. This is identification. //4 4. For plants, scientific names are based on agreed principles and criteria, which are provided in International Code for Botanical Nomenclature (ICBN). //4 5. Animal taxonomists have evolved International Code of Zoological Nomenclature (ICZN). //4 6. The scientific names ensure that each organism has only one name. //4 7. Each name has two components – the Generic name and the specific epithet. //4 8. This system of providing a name with two components is called Binomial nomenclature. //4 9. This naming system given by Carolus Linnaeus is being practised by biologists all over the world. //4 10. Biological names are generally in Latin and written in italics. //4 11. The first word in a biological name represents the genus while the second component denotes the specific epithet. //4 12. Both the words in a biological name, when handwritten, are separately underlined, or printed in italics to indicate their Latin origin.//4 13. The first word denoting the genus starts with a capital letter while the specific epithet starts with a small letter. //5 14. Name of the author appears after the specific epithe e.g., Mangifera indica Linn. //5 15. Classification is the process by which anything is grouped into convenient categories based on some easily observable characters. //516. ‘Dogs’, ‘Cats’, ‘Mammals’, ‘Wheat’, ‘Rice’, ‘Plants’, ‘Animals’, etc., are convenient categories we use to study organisms. The scientific term for these categories is taxa. //5 17. taxa can indicate categories at very different levels. //5 18. based on characteristics, all living organisms can be classified into different taxa. This process of classification is taxonomy. //5 19. modern taxonomic studies include External and internal structure, along with the structure of cell, development process and ecological information of organisms. //5 20. characterisation, identification, classification and nomenclature are the processes that are basic to taxonomy. //5 21. study of not only interested in knowing more about different kinds of organisms and their diversities, but also the relationships among them is called systematics. //5 22. word ‘systema’ which means systematic arrangement of organisms. //5 23. Linnaeus used Systema Naturae as the title of his publication. //6 24. Systematics takes into account evolutionary relationships between organisms. //6 25. Classification is not a single step process but involves hierarchy of steps in which each step represents a rank or category. //6 26. Since the category is a part of overall taxonomic arrangement, it is called the taxonomic category. //6 27. all categories together constitute the taxonomic hierarchy. //6 28. Each category, referred to as a unit of classification, in fact, represents a rank and is commonly termed as taxon (pl.: taxa). //6 29. Each rank or taxon, in fact, represents a unit of classification. //6 30. These taxonomic groups/ categories are distinct biological entities and not merely morphological aggregates. //6 31. Taxonomical studies of all known organisms have led to the development of common categories such as kingdom, phylum or division (for plants), class, order, family, genus and species. //6 32. This helps in identifying similarities and dissimilarities among the individuals of the same kind of organisms as well as of other kinds of organisms. //6 33. Taxonomic studies consider a group of individual organisms with fundamental similarities as a species.//6 34. Each genus may have one or more than one specific epithets representing different organisms, but having morphological similarities. //6 35. one species differs from the other closely related species based on the distinct morphological differences. //6 36. Genus comprises a group of related species which has more characters in common in comparison to species of other genera. //7 37. Family, has a group of related genera with still less number of similarities as compared to genus and species. //7 38. Families are characterised on the basis of both vegetative and reproductive features of plant species. //7 39. order and other higher taxonomic categories are identified based on the aggregates of characters. //7 40. Order being a higher category, is the assemblage of families which exhibit a few similar characters. //7 41. The similar characters are less in number in order as compared to different genera included in a family. //7 42. class category includes related orders. //7 43. All these (fishes, amphibians, reptiles, birds along with mammals) based on the common features like presence of notochord and dorsal hollow neural system, are included in phylum Chordata.//844. In case of plants, classes with a few similar characters are assigned to a higher category called Division. //8 45. All animals belonging to various phyla are assigned to the highest category called Kingdom. //8 46. as we go higher from species to kingdom, the number of common characteristics goes on decreasing. //8 47. Lower the taxa, more are the characteristics that the members within the taxon share. //8 48. Higher the category, greater is the difficulty of determining the relationship to other taxa at the same level. //8