Table of contents |
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Building Blocks of Life And Their Functions |
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Systematics |
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Nomenclature |
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ICBN -“International Code of Botanical Nomenclature” |
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Taxonomic Categories |
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Taxonomic Aids |
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Role of Water
Role of Oxygen
Role of Sodium Chloride (common salt)
Role of Carbohydrates
Role of Proteins
Role of Lipids
Role of Nucleic Acid
Example: Morphological characters of root, stem, leave flowers.
New systematics or Neo systematics or Biosystematics is a new branch. Its name was given by Julian Huxley (1940).
The term 'taxonomy' was coined by A. P. de Candolle.
Taxonomy is of 6 types:
Taxonomic Categories(i) Alpha taxonomy: Only morphological characters are used for the identification and classification of plants.
(ii) Beta taxonomy: Involves genetical, anatomical, cytological, palynological, physiological and other characters.
(iii) Omega taxonomy: Analysis and synthesis of all information and types of data to develop a classification system based on the phylogenetic relationship.
(iv) Cytotaxonomy: The use of cytological characters of plants in classification or in solving taxonomic problems is called Cytotaxonomy.
(v) Chemotaxonomy: The use of chemical compounds present in plants for classification or in solving taxonomic problems is called Chemotaxonomy or chemical taxonomy. The basic chemical compounds used in chemotaxonomy are alkaloids, carotenoids, tannins, polysaccharides, nucleic acids, fatty acids, aromatic compounds etc.
(vi) Karyotaxonomy: It is based on the characters of the nucleus and chromosomes. The pattern of chromosome bands (dark bands and light bands) is the most specific character for classification of organisms.
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Linnaean Classification System
(i) Species: It is the smallest taxonomic category. It is the basic unit of classification. It is the group of population which is similar in shape, form and reproductive features. Due to the same reproductive features, the fertile sibling can be produced.
(ii) Genus: It is an assembly of a group of similar species which involved from a common ancestor and have certain common characters called correlated characters. But it is not mandatory to have many species. Monotypic genera have only one species. Polytypic genera have more than one species.
Example: Cat and leopard are put in the genus Panthera.
(iii) Family: It is the collection of similar genera. Families are characterised on the basis of reproductive and vegetative features. For example, the lion and tiger are included in the family Felidae.
(iv) Order: Being a higher category is the assembly of one or more than one similar families. Family Felidae is included in the order Carnivora.
(v) Class: A class is a subdivision within a phylum made of one or more than one order. Class Mammalia includes all mammals which are monkey, gorilla, gibbon and man.
(vi) Phylum: It comprises of a collection of similar classes. Phylum Chordata of animals has class Mammalia along with fishes, reptiles, birds, and amphibians.
(vii) Kingdom: All animals belonging to various phyla are assigned to the topmost taxonomic category called kingdom. Example all animals are included in Kingdom Animalia. All plants are included in kingdom Plantae. The unit that denotes grouping of the organism based on observable features is known as Taxon.
Major Botanical Gardens
1. What are the building blocks of life and their functions? | ![]() |
2. What is the International Code of Botanical Nomenclature? | ![]() |
3. What are taxonomic categories? | ![]() |
4. What are some taxonomic aids? | ![]() |
5. What is systematics? | ![]() |