9th Class Science Notes in English chapter 7 Diversity in Living Organism

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9th Class Science Notes in English chapter 7 Diversity in Living Organism


CBSE Revision Notes for CBSE Class 09 Science Diversity in Living Organisms: Diversity of plants and animals - basic issues in scientific naming, basis of classification. Hierarchy of categories / groups, Major groups of plants (salient features) (Bacteria, Thallophyta, Bryophyta, Pteridophyta, Gymnosperms and Angiosperms). Major groups of animals (salient features) (Non-chordates upto phyla and chordates upto classes).


Class 9th Science chapter 7 Diversity in Living Organism Notes in English


πŸ“š Chapter - 7 πŸ“š
πŸ‘‰ Diversity in Living Organism πŸ‘ˆ


✳️Diversity:-


πŸ”Ή Diversity is the presence of different organisms in the same ecosystem or geographical location.

πŸ”Ή Diversity gives a chance for a more balanced ecosystem.


✳️Biodiversity:-


πŸ”Ή The variety of animals and plants living in a given geographical area is called biodiversity of that geographical area.


✳️Taxonomy:-


πŸ”Ή It is a branch of biology which deals with identification, nomenclature, and classification of organisms.

πŸ”Ή Carolus Linnaeus is called the father of Taxonomy )

✳️Classification:-


πŸ”Ή The method of arranging organisms into groups or sets on the basis of similarities and differences is called classification.


✳️Evolution:-


πŸ”Ή Evolution is the slow process by which the organisms change according to the needs to survive the environment around them.


✳️Importance of classification:-


πŸ”Ή It makes the study of wide variety of organisms easy and in systematic manner.

πŸ”Ή It helps to understand how the different organisms have evolved with time.

πŸ”Ή It helps to understand the relationships between different groups of organisms.

πŸ”Ή It forms a base for the study of other biological sciences, like biogeography.


✳️Basis of classification:-


πŸ”Ή There are the certain features or properties used for the classification of living organisms which are known as characteristics.

πŸ”Ή Organisms with same characteristics are placed in same groups.


✳️Hierarchy of Classification:- 


πŸ”Ή Linnaeus proposed a classification system by arranging organisms into taxonomic groups at different levels according to the characteristics they have.


✳️Classification System:-


πŸ‘‰ Two kingdom classification:- Carolus Linnaeus in 1758 classified the living organisms into two groups as plants and animals.


πŸ‘‰ Type of cellular organization:-


πŸ”Ή a) Prokaryotic cells: These are primitive incomplete cells without well-defined nucleus. 

πŸ”Ή b) Eukaryotic cells: These are advanced and complete and cells with well defined nucleus.


πŸ‘‰ Body organization:-


πŸ”Ή a) Unicellular organisms: These are organisms made up of single cell with all activities performed by the single cell. 

πŸ”Ή b) Multicellular organisms: These are organisms made up of large number of cells with different functions performed by different cells.


πŸ‘‰ Mode of obtaining food:-


πŸ”Ή a) Autotrophs: These are the organisms that make their own food by photosynthesis. 

πŸ”Ή b) Heterotrophs: These are the organisms which depend on other organisms for food.


✳️Nomenclature:- An organism can have different names in different languages. This creates confusion in naming organism. A scientific name is needed which is same in all languages. Binomial nomenclature system given by Carolus Linnaeus is used naming different organisms.


✳️Following are some conventions in writing the scientific names:-


πŸ”Ή 1. Genus should be written followed by the species. 

πŸ”Ή 2. First letter of the genus should be capital and that of the species should be in small letter. 

πŸ”Ή 3. When printed the name should be written in italics and when written with hands genus and species should underlined separately. 

πŸ”Ή Example: Homo sapiens for humans, 

                       Panthera tigris for tiger


✳️Five kingdom classification:-


πŸ”Ή H. Whittaker in 1959 classified the organisms into five kingdoms as (i) Kingdom Monera, (ii) Kingdom Protista, (iii) Kingdom Fungi, (iv) Kingdom Plantae and (v) Kingdom Animalia.


πŸ‘‰ Kingdom Monera:-


πŸ”Ή (i) Type: Unicellular Prokaryotic 

πŸ”Ή (ii) Mode of nutrition: Autotrophic or heterotrophic 

πŸ”Ή (iii) Body: Lack well-defined nucleus and cell organelles 

πŸ”Ή (iv) Examples: Anabaena and Bacteria, Blue-green algae

9th Class Science Notes in English chapter 7 Diversity in Living Organism

πŸ‘‰ Kingdom Protista:-


πŸ”Ή (i) Type: Unicellular Eukaryotic 

πŸ”Ή (ii) Mode of nutrition: Autotrophic or Heterotrophic 

πŸ”Ή (iii) Body: Some organisms use pseudopodia or cilia or flagella for movement 

πŸ”Ή (iv) Examples: Amoeba, Paramecium, Euglena

9th Class Science Notes in English chapter 7 Diversity in Living Organism

πŸ‘‰ Kingdom Fungi:-


πŸ”Ή (i) Type: Multicellular Non-green Eukaryotic 

πŸ”Ή (ii) Mode of nutrition: Saprophytic or Parasitic Sometimes symbiotic 

πŸ”Ή (iii) Body: Fungus is made up of long filaments called hyphae. The network of hyphae is mycelium. 

πŸ”Ή (iv) Examples: Yeast, Pencilium, Agaricus, Mushrooms moulds 

9th Class Science Notes in English chapter 7 Diversity in Living Organism

πŸ‘‰ Kingdom Plantae:-


πŸ”Ή (i) Type: Multicellular Eukaryotic 

πŸ”Ή (ii) Mode of nutrition: Autotrophic 

πŸ”Ή (iii) Body: Exhibits high level of tissue differentiation and have specialized body organs.

πŸ”Ή (iv) Examples: Trees, Plants, Shrubs 


9th Class Science Notes in English chapter 7 Diversity in Living Organism

πŸ‘‰ Kingdom Animalia:-


πŸ”Ή (i) Type: Multicellular Eukaryotic 

πŸ”Ή (ii) Mode of nutrition: Heterotrophic 

πŸ”Ή (iii) Body: Exhibits high level of tissue differentiation and have specialized body organs. They have well developed nervous system. 

πŸ”Ή (iv) Examples: Fish, Insects, Animals, Humans, Birds

9th Class Science Notes in English chapter 7 Diversity in Living Organism


✳️Some Important Points:-


πŸ‘‰ Phanerogam:- Plants with seeds are called phanerogam. They contains embryo with stored food and are multicellular.


πŸ‘‰ Cryotogam:- Plants with spores are called cryptogam. They contains only naked embryo and are generally unicellular


πŸ‘‰ Gymnosperms:- These are plants with naked seeds and do not bear flowers. These types of plants are perennial, evergreen and woody. Example- Pinus, Cycus etc. 


πŸ‘‰ Angiosperms:- These are plants with seeds inside the fruit and bears flowers. Embryos in seed have structure called cotyledons. 


πŸ”Ή Angiosperms are further divided on the basis of number of cotyledons into two parts i.e., Monocots and Dicots.

9th Class Science Notes in English chapter 7 Diversity in Living Organism


πŸ‘‰ Arthropoda:- Arthropoda is the largest phylum which consist of 80% species. Scorpio, Cockroach, Housfly, Butterfly, Spider etc are example of arthropoda species.


πŸ‘‰ Annelida:- Annelida is second largest phylum. Earthworm, leech nereis arΔ— example of annelida species. 


πŸ‘‰ Taxonomy:- Taxonomy is a branch of biology which deals with identification, nomenclature and classification of organisms. 


πŸ‘‰ Carolus Lannaeus:- Carolus Lannaeus is called the father of Taxonomy. 


✳️Vertebrata:-


πŸ”Ή Vertebrata:- Vertebrata are those animals which have have a chord like structure (vertebral column present in their body). 


πŸ”Ή Vertebrates are divided into five classes namely (i) Pisces, (ii) Amphibia, (iii) Reptilia, (iv) Aves and (v) Mammalia.


πŸ‘‰ Pisces (Fishes)


πŸ”Ή They are fishes living in water. 

πŸ”Ή Their skin is covered with scales or plates. 

πŸ”Ή They respire using gills. 

πŸ”Ή They are cold blooded and their heart has only two chambers. 

πŸ”Ή They lay eggs from which the young ones hatch out 

πŸ”Ή Example: Sharks, Rohu etc. 

9th Class Science Notes in English chapter 7 Diversity in Living Organism
9th Class Science Notes in English chapter 7 Diversity in Living Organism

πŸ‘‰ Amphibia (Amphibians)


πŸ”Ή They are found in land and water. 

πŸ”Ή They are cold blooded and the heart is three chambered. 

πŸ”Ή Respiration is through gills or lungs. 

πŸ”Ή They lay eggs in water. 

πŸ”Ή Example: Frogs, Toads, Salamanders etc. 

9th Class Science Notes in English chapter 7 Diversity in Living Organism


πŸ‘‰ Reptilia (Reptiles)


πŸ”Ή They have scales and breathe through lungs. 

πŸ”Ή They are cold blooded. 

πŸ”Ή Most of them have three chambered heart but crocodiles have four chambered heart. 

πŸ”Ή They lay eggs with hard covering in water. 

πŸ”Ή Example : Snakes, Turtles, Lizards, Crocodiles etc.

9th Class Science Notes in English chapter 7 Diversity in Living Organism


πŸ‘‰ Aves (Birds)


πŸ”Ή They are warm blooded animals. 

πŸ”Ή They have four chambered heart. 

πŸ”Ή They breathe through lungs. 

πŸ”Ή They have an outer covering of feathers. 

πŸ”Ή Their two fore limbs are modified into wings for flying. 

πŸ”Ή They lay eggs. 

πŸ”Ή Example: Crow, Sparrow, Pigeon, Duck, Stork, Ostrich etc.

9th Class Science Notes in English chapter 7 Diversity in Living Organism


πŸ‘‰ Mammalia (Mammals)


πŸ”Ή They are warm blooded animals. 

πŸ”Ή They have four chambered heart. 

πŸ”Ή They have mammary glands for production of milk to nourish their young ones. 

πŸ”Ή The skin has hairs and sweat glands. Most of them give birth to their young ones. 

πŸ”Ή Some of them lay eggs (like Platypus and Echidna). 

πŸ”Ή Example: Cat, Rat, Dog, Lion, Tiger, Whale, Bat, Humans etc. 

9th Class Science Notes in English chapter 7 Diversity in Living Organism

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