Important Questions Class 9 Science Chapter 7 Diversity in Living Organisms

Notes for Class 9

Please refer to Diversity in Living Organisms Class 9 Science Notes and important questions below. The Class 9 Science Chapter wise notes have been prepared based on the latest syllabus issued for the current academic year by CBSE. Students should revise these notes and go through important Class 9 Science examination questions given below to obtain better marks in exams

Diversity in Living Organisms Class 9 Science Notes and Questions

The below Class 9 Diversity in Living Organisms notes have been designed by expert Science teachers. These will help you a lot to understand all the important topics given in your NCERT Class 9 Science textbook.

Refer to Chapter 7 Diversity in Living Organisms Notes below which have been designed as per the latest syllabus issued by CBSE and will be very useful for upcoming examinations to help clear your concepts and get better marks in examinations.

1. Each organism is different from all other organisms.

2. The presence of various forms of plants and animals is known as diversity.

3. Greek thinker Aristotle classified animals according to whether they lived on land,in water or in air. This classification is a landmark in ideology, but has limitations. For example, animals that live in the sea include Corals, Whales, Octopus, Starfish, and Shark. In fact they are different from each other.

4. Classification and Evolution: organisms are classified based on body design, hierarchy in developing, relation to evolution. Charles Darwin first described the idea of evolution in 1859 in his book “ The Origin of Species” 5. The Biologists, such as Haeckel, Whittaker & Carl Woese tried to classify all living organisms into broad Kingdoms. The Whittaker proposed five kingdoms: Monera, Protista, Fungi, Plantae and Animalia. Carl Woese

introduced by dividing Monera into Archaebacteria and Eubacteria.

6. Hierarchy of Classification :

Linnacus’s System of Classification Kingdom↓Phylum↓Class↓Order↓family↓Genus↓SpeciesKingdom↓Phylum↓Class↓Order↓family↓Genus↓Species

7. Monera: They have unicellular, Prokaryotic organisms (do not have defined nucleus or organelles). The cell wall may or may not present. The mode of nutrition is autotrophic (synthesizing food on their own) (or)heterotrophic (getting food from environment). Ex. Bacteria, Anabaena.

8. Protista: They have unicellular eukaryotic organisms (do have well defined nucleus or organelles). The body is covered by cilia, flagella for locomotion. The mode of nutrition is autotrophicorheterotrophic. Ex. Diatoms, protozoans.

9. Fungi: These are multi-cellular eukaryotic organisms with cell wall, made up of

Chitin. They do not perform Photosynthesis (heterotrophic),Saprophytic (derive nutrition from decaying material). Ex. Aspergillus, Penicillium, Mushroom, Rhizopus. The fungi living with algae forms Lichen (Symbiotic Association)

10. Plantae: These are multi-cellular eukaryotic organisms with cell wall, made up of Cellulose. Able to perform photosynthesis (autotrophic). Ex. Rice, wheat.

11. Animalia:These are multi-cellular eukaryotic organisms without cell wall. They are not able to perform photosynthesis (heterotrophic). Ex Human beings, Peacock.


1. The kingdom Plantae is further classified as Thallophyta, Bryophyta, Pteridophyta, Gymnosperms, Angiosperms .

2. Thallophyta: The plants do not have well defined body design, commonly called as”

Algae”, mostly aquatic. Ex. Spirogyra, Ulothrix.

3. Bryophyta: These are commonly called as the “Amphibians of Kingdom”. The plant body is differentiated into roots like, stem like and leaf like structures. No specialized tissues for the conduction of water and food.Ex. Marchantia, Funaria.

4. Pteridophyta: These are commonly called as the “First vascular land plants ”. The plant body is differentiated into root, stem and leaf. Specialized tissues for the conduction of water and food are developed in these plants. The reproductive organs are inconspicuous. Ex. Marsilea, Fern.

Special Note: The reproductive organs are inconspicuous in Thallophyta, Bryophyta,72 Pteridophyta are can’t develop seeds. They are together called as” Cryptogamae (Non- Flowering Plants)”. The plants with well differentiated reproductive organs and thatultimately make seeds are called” Phanerogams (Flowering Plants)”. This group is further classified Gymnosperms (Bear naked Seeds) &Angiosperms (Bears seeds inside Fruit).

5. Gymnosperms: These are commonly called as “Naked seed bearing plants”. They areusually perennial, evergreen and woody. Ex. Pinus, Cycas

6. Angiosperms: These are commonly called as “Enclosed seed bearing plants”. Plants with seeds having a single cotyledon are called as” Monocotyledons or Monocots”. Plants with seeds having two cotyledons are called as “Dicots”. Ex. Ipomoea, Paphiopedium.


These are Eukaryote, multicultural and hetero-tropic.

They are further classified as Non-Chordates( Porifera, Coelenterata, Platyhelminthes , Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata) and Chordates { Protochordata, Vertebrata ( Pisces, Amphibians, Reptilia, Aves, Mammalia)} .

I. Non- Chordates

1. Porifera: The word Porifera” means organisms with holes”. The canal system helps in circulating water, food, oxygen. They are non-motile with cellular level of organization and mainly marine organisms with hard outer coat called as Skeleton. They are commonly called as Sponges. Ex. Spongilla, Sycon.

2. Coelenterata: The word Coelenterata” means organisms with body cavity Called Coelenteron”. They are radially symmetrical, Diploblastic (two layers of cells), commonly called as Cnidarians (Stinging cells for protection are present in the body). Ex. Hydra, Sea Anemone.

3. Platyhelminthes: The word Platyhelminthes means organisms with flatworms (dorsocentrally flattened)”. They are bilaterally symmetrical Triploblastic (three layers of cell), either free-living or parasitic. No true Coelom is present – Acoelomates. Ex. Planaria (Free living), Tape worm( Parasitic)

4. Nematoda: The word Nematoda “means organisms with roundworms”. They are bilaterally symmetrical Triploblastic (three layers of cells), familiar with parasitic worms. The false Coelom is called as Pseudocoelome. Ex. Ascaris, Wuchereria (Filarial worm causes elephantiasis).

5.Annelida: The word Annelida “ means organisms with metameric-segmented”. They are bilaterally symmetrical Triploblastic (three layers of cells) with closed circulatory system, familiar with earth worms. The Coelom is called as true Coelom. Ex. Neris, Earth worm, Leech .6. Arthropoda: The word Arthropoda “means organisms with jointed legs” They are bilaterally symmetrical Triploblastic(three layers of cells ), familiar with cockroaches. The Coelom is blood filled called as Haemo Coelom. Ex. Prawn, Scorpion, Housefly.

7. Mollusca: The word Mollusca “means organisms with soft body” They are bilaterally symmetrical, Triploblastic(three layers of cells), familiar with Octopus, Pila. Foot is for moving, kidney like organ for excretion, with open circulatory system. Ex. Unio, chiton.

8. Echinodermata: The word Echinodermata “means organisms with spiny skinned”. Exoskeleton is with calcium carbonate. They are radially symmetrical Triploblastic (three layers of cells) with coelomic cavity, familiar with Star fish. They are exclusively free-living marine animals. Ex. Sea Cucumber, Feather Star .

II.Chordates: They are further classified as two major groups such as Protochordata &Vertebrata

(A).Protochordata: Notochord present in at least larval forms, but very rudimentary. It is a rod like supporting structure, runs along with nervous tissue from the gut of animal. They are bilaterally symmetrical, triploblastic (three layers of cells) with a Coelom, familiar with Amphioxus. Ex. Balanoglossus.

(B).Vertebrata: Notochord is replaced by vertebral column and internal skeleton. They are bilaterally symmetrical, triploblastic, coelomic and segmented having paired gill pouches. Vertebrates are grouped into five classes.

1. Pisces: These are commonly called as “fishes”, exclusively aquatic. Body is streamlined and a tail for locomotion. Gills for respiration, heart is two chambered, cold blooded, skin is covered with scales, plates. They are cold-blooded animals. Skeleton of bone ( Rohu) / cartilage( Shark). They lay eggs. Ex. Lion Fish, Dog Fish.

2. Amphibians: These are commonly called as “Amphibians” because they can live on land and in water”. Body is streamlined and a webbed foot/ foot for locomotion. Gills or lungs or skin for respiration, heart is three chambered, cold blooded, skin is lack of scales, plates. They are cold-blooded animals. They lay eggs. Ex. Rana, Hyla .

3. Reptilia: These are commonly called as “Reptilians”. A lung for respiration, heart is three chambered (Crocodile heart is four chambered), skin have scales. They are cold-blooded animals. They lay eggs. Ex. Snakes, Turtles

4. Aves :These are commonly called as “Birds”. A lung for respiration, heart is fourchambered, fore limbs are modified for flight, skin has feathers. They are warm-blooded animals. They lay eggs. Ex. Ostrich (Flightless Bird), Pigeon, Sparrow .

5. Mammalia: These are commonly called as “animals with mammary glands for producing
milk to nourish their young ones”. A lung for respiration, heart is four chambered, skin has

hairs, sweat or oil glands. They are warm-blooded animals. They lay eggs (Platypus, Echidna), give birth to young ones poorly developed (Kangaroo) & give birth to developedyoung ones (Human beings). Ex. Lion, Whale, Bat


NOMENCLATURE: The system of scientific naming or nomenclature was introduced by Carolus Linnaeus. It is unique to identify in the world. We limit ourselves to writing the names of the Genus and Species of that particular organism. The world over, it has been agreed that both these names will be used in Latin forms.When printed is given in italics and when written by hand, the Genus and Species name have to be underlined separately. Ex. Human (Common name): Home sapiens (scientific name with two parts namely the Genus and Species).

Questions for Class 9 Science Chapter 7 Diversity in Living Organisms

Question. Write the general characteristics of kingdom – fungi.
Ans :
(1) The fungi are the unique heterotrophic organisms either saprophytic or parasitic or symbiotic.
(2) The fungi are cosmopolitan in distribution and occur in air, water, soil and on plants and animals.
(3) They are unicellular (yeast) or multicellular, eukaryotic organisms.
(4) Fungi are filamentous and the body consisting of long, slender thread-like structures called hyphae, may be coenocytes hyphane or septate hyphore.
(5) The network of hyphae in fungi is called mycelium.
(6) The cell walls of fungi are composed of chitin and polysaccharides.
(7) Reproduction in fungi can take place by three methods :
(a) Vegetative
(b) Asexual
(c) Sexual reproduction.

Question. What is the basis for classification of organisms?
Ans : The basis for classification are :
(a) Presence or absence of nucleus.
(b) Organisms are unicellular, or multicellular.
(c) Autotrophic mode of nutrition or heterotrophic mode of nutrition.
(d) Of the organisms that perform photosynthesis (plants), their level, or organisation of the body.
(e) Of the animals, how does the individuals body develop and organise its different parts.

Question. A group of students had gone for educational trip clicked photographs of endangered plants. These photographs were used by the school laboratory to study these plants.
(i) Name two endangered plants.
(ii) Name any one medicinal plant and give its medicinal use.
Ans :
(i) Two endangered plants are Euphrasia and Ubnus rubra.
(ii) Aloe-vera : Juice of Aloe-vera is used in case of indigestion, treating skin infection, etc.

Question. Mention the main criteria of R.H. Whittaker’s classification.
Ans : (1) Cell structure;
(2) Thallus organization;
(3) Mode of nutrition;
(4) Reproduction;
(5) Phlogenetic relationships were considered by Whittaker.

Question. Name the phylum of the following organisms, whose exclusive characteristics is given below :
(a) Hollow bones
(b) Jointed appendages
(c) Flatworm
(d) Round worms, parasitic
(e) Soft body, muscular marine animal
(f) Radially symmetrical, spiny skin.
Ans :
(a) Phylum chordata, subphylum—vertebrata,

Question. Give the characteristic features of Echinodermata.
Ans : (a) Spikes present on skin.
(b) Free living, marine animals.
(c) Triploblastic and have a coelomic cavity.
(d) Have a peculiar water driven tube system used for moving around.
(e) Have hard calcium carbonate structure that is used as a skeleton.
Examples : Starfish, sea-urchin.

Question. Give specific characteristics of Coelenterate.
Ans :
(a) Water living animals.
(b) Body is made of two layers of cells.
(c) Some of them live in colonies (corals), while others have solitary life-span (Hydra).
(d) Body cavity present.
(e) Radially symmetrical.

Question. Name the phylum of the following animals :
(a) Tapeworm
(b) Starfish
(c) Jellyfish
(d) Octopus
Ans :
(a) Tapeworm — Platyhelminthes
(b) Starfish — Echinodermata
(c) Jellyfish — Coelenterata
(d) Octopus — Mollusca

Question. Name the 5 kingdoms of living organisms.
Ans :
1. Monera;
2. Protista;
3. Fungi, mycota;
4. Plantae; Metaphyto;
5. Animalia Metazoa.

Question. Name the kingdom which includes eukaryotic heterotrophic organisms.
Ans : Kingdom Mycota (Fungi).

Question. Name unicellular fungi.
Ans : Yeast.

Question. Who proposed the classification of organisms into 5 kingdoms?
Ans : Robert H. Whittaker proposed the classification of organisms into 5 kingdoms in 1959.

Question. Name the appendages used for movement by organism belonging to Protista kingdom.
Ans : (a) Paramecium – Cilia
(b) Euglena – Flagella
(c) Amoeba – Pseudopodia

Question. Give simple classification of plant kingdom.
Ans : Kingdom plantae is divided in following divisions :
(a) Thallophyta
(b) Bryophyta
(c) Pteridophyta
(d) Phanerogams
(i) Gymnosperm
(ii) Angiosperm – (1) Monocots (2) Dicots

Question. Who proposed the two kingdom classification?
Ans : Carolus Linnaeus proposed the two kingdom classification.

Question. What is lichen?
Ans : Lichen is the symbiotic association of fungi and bluegreen algae.

Question. Why bryophytes and pteriodophytes grow in moist and shady places?
Ans : Bryophytes and pteriodophytes need water for their reproduction. Because reproduction in these organisms can take place when water helps in carrying male gamete to female gamete.

Question. Name the writer who wrote the book “The Origin of Species”.
Ans : Charles Darwin wrote the book “The Origin of Species” in 1859.

Question. Give examples of the organism belonging to Monera and Protista kingdom.
Ans : Monera — Anabaena, blue-green algae.
Protista — Euglena, Paramecium, Amoeba.

Question. Give examples of pteridophyte.
Ans : Marsilea and fern.

Question. Write the name of three mammals that live in water.
Ans : Whale, platypus and dolphins.

Question. Write the salient features of protozoans.
Ans :
(1) All protozoans are eukaryotic, microscopic, unicellular.
(2) They are heterotrophic, live as predators or parasites (plasmodium and Trypanosoma).
(3) They are believed to be primitive relatives of animals.
(4) Protozoans are grouped into four major groups, such as :
(p) Amoeboid protozoans
(q) Flagellated protozoans
(r) Ciliated protozoans
(s) Sporozoans

Question. What is the importance of classification?
Ans : Classification is important because :
(a) Classification makes the study of wide variety of organisms systematic and easier.
(b) It projects a picture of all organisms and their interrelation with each other.
(c) It provides a base for the study of other branches of biology.
(d) It is useful in the study of ecology, which deals with the inter-relation of an organism with their environment.
(e) It helps to establish a hierarchy of groups of organisms.

Question. What are parasites? Name two protozisum parasites you have studied.
Ans : The organisms which depend on the other host organism for their requirement of food are called parasites.
Examples : (1) Plasmodium, (2) Trypanosoma.

Question. Give the characteristics of mammals.
Ans :
(a) Mammals are warm-blooded animals.
(b) Four-chambered heart.
(c) Mammary glands for production of milk to nourish their younger one.
(d) Skin has hairs, sweat glands and oil glands.
(e) Most of them produce their young ones (viviparous).

Question. Give the characteristics of Protista.
Ans : (a) Organisms are unicellular and eukaryotic.
(b) Locomotion is possible by using parts like cilia, flagella, etc.
(c) Nutrition is either autotrophic or heterotrophic.
(d) E.g., algae, protozoa.

Question. Why should we keep fruits and vegetables in refrigerator?
Ans : To prevent food from getting bad due to bacterial or fungal infections.

Question. Name the cell wall component of fungi.
Ans : Chitin and polysaccharides.

Question. Give an example for flagellated protozoans.
Ans : Trypanosoma, Euglena.

Question. Name parasitic flagellated protozoan.
Ans : Trypanosoma

Question. Name the kingdom which includes monerans.
Ans : Kingdom Monera.

Question. Give an example for kingdom Monera.
Ans : Bacteria, Nostoc, Mycoplasma.

Question. What are unicellular organisms? Give an example for unicellular organisms?
Ans : One celled or Single celled organisms are called unicellular organisms.
Example : Chlamydomonas, Amoeba, Euglena.

Question. What is evolution?
Ans : Evolution is the change in heritance characteristics of organism over generations.

Question. Who made 1st attempt for scientific basis of classification?
Ans : Aristotle.

Question. On what morphological criteria Aristotle classified the plants?
Ans : Based on the morphological nature of the stem.

Question. What is biodiversity?
Ans : Various types of living organism found in a particular region is called biodiversity.

Question. Name the reproductive organ of plants.
Ans : Flower.

Question. What are gymnosperms?
Ans : Gynosperms are the group of plants that bear naked seeds, e.g., pines, deodar.

Question. What are cotyledons?
Ans : Plant embryos in seeds have structures called cotyledons. Cotyledens are also known as seed leaves.

Question. Name the five kingdoms of living organisms?
Ans :
(1) Kingdom — Monera,
(2) Kingdom — Protista,
(3) Kingdom — Fungi (mycota),
(4) Kingdom — Plantae (metaphyta),
(5) Kingdom — Animalia (metazoan).

Question. Define radial symmetry.
Ans : When any plane axis passing through the central axis of the body divides the animal into two halves that are mirror image, is called radial symmetry. For example : sponges, starfish.

Question. Give example of two fish which have skeleton made up of both bone and cartilage.
Ans : Tuna and rohu.

Question. What is biological classification?
Ans : Grouping of organisms based on similarities and dissimilarities is called biological classification.

Question. What are heterotrophic bacteria?
Ans : The bacteria which do not synthesize their own food but depend on other organisms or dead organic matter are called heterotrophic bacteria.

Question. Due to global warming coral is getting diminished in all the oceans/ water bodies. People in Lakshadweep island protects their corals by not allowing people/ tourist to take few pieces away.
(a) Name the phylum of coral.
(b) What is coral made up of?
(c) What values of people in Lakshadweep island is reflected?
Ans :
(a) Phylum of coral is coelenterata.
(b) Coral is made up of calcium carbonate.
(c) People in Lakshadweep island reflect the value of being responsible (Citizen, respecting environment and nature).

Question. What are cyano bacteria?
Ans : Bacteria that obtain their energy through photosynthesis.

Question. What is diatomaceous earth?
Ans : Accumulation of cell wall deposition of dead diatoms.

Question. Which are chief producer of oceans?
Ans : Diatoms.

Question. Write the characteristic features of the kingdom – protista.
Ans :
(1) All protists are single celled eukaryotes.
(2) It includes plant protist (photosynthetic protozoans) and animal protists.
(3) Protist members are primarily agnatic in nature and some are Parasitic.
(4) The kingdom protista links with other plants, fungi and animals.
(5) Same protistans members have flagella or cilia as locomotory organs.
(6) Protists reproduce asexually by binary fission and sexually by aprocose involving cell fusion and Zygote formation

Question. Give the characteristics of amphibians.
Ans : Amphibians are vertebrates that live on land and in water.
(a) They are cold-blooded.
(b) Heart is three-chambered.
(c) Fertilization is external.
(d) Respiration through lungs on land and through moist skin when in water. Examples : Frog, Toads.

Question. Write the two characteristic features of kingdom protista?
Ans : (1) All are single celled eukaryotes.
(2) It includes plant protists (photosynthetic protozoan) and animal protozoan’s (protista).
(3) Some prostistan members have flagella or cilia as locomotary organs.
(4) Protists reproduce asexually by binary fission and sexually by a process involving cell fission and zygote formation.

Question. Why do most of the amphibians lay their eggs in water while reptiles lay their eggs on land?
Ans : Amphibians lay their eggs in water because the young ones have gills in initial stages of hatching out of egg by that they can breathe in water. But in case ofreptiles the young ones’ need warmth in initial stages of hatching out of egg so the reptiles lay their eggs on land.

Question. What are the characteristic features of reptiles?
Ans :
The characteristics of reptiles :
(a) Dry scaly, impermeable skin.
(b) Respiration through lungs.
(c) Cold-blooded
(d) Internal fertilization.
(e) Heart is three chambered.
(f) Two pairs of pentadactyl limbs are present.

Question. Which is the locomotory organ of paramecium or ciliated protozoans.
Ans : Cilia.

Question. Give one example for sporozoan.
Ans : Plasmodium.

Question. What are the conventions followed for writing the scientific names?
Ans : The conventions followed while writing the scientific names are :
1. The name of the genus begins with a capital letter.
2. The name of the species begins with a small letter.
3. When printed, the scientific name is given in italic.
4. When written by hand, the genus name and the species name have to be underlined separately.
(b) Phylum—Arthropoda
(c) Phylum—Platyhelmithes
(d) Phylum—Aschelminthes
(e) Phylum—Mollusca
(f) Phylum—Echinodermata

Question. Identify the phylum for the following characteristics given :
(a) Organisms with joint appendages.
(b) Organisms are generally flatworms.
(c) Body is segmented.
(d) Skin of organisms is full of spikes.
Ans :
(a) Arthropoda
(b) Platyhelminthes
(c) Annelida
(d) Echinodermata.

Question. What are parasitic fungi?
Ans : The heterotrophic fungi which absorb food from living plants and animals are called parasitic fungi.

Question. What are symbionts?
Ans : The association of 2 organisms in which both the organisms are mutually benefited are called symbionts.
Example : Fungi with algae as lichens.

Question. Give an example for euglenoids.
Ans : Euglena (photosynthetic protozoan).

Question. What are slime moulds?
Ans :Saprophytic protists are called slime moulds.

Question. Name the kingdom which includes single celled eukaryotes.
Ans : Kingdom Protista.

Question. Name the 2 methods of protistan’s reproduction.
Ans : (1) Asexual reproduction (cell fusion),
(2) Sexual reproduction (zygote formation).

Question. What are prokaryotes? Give one example for prokaryote.
Ans : The organisms which do not have well organized nucleus in their cell are called prokaryotes. Organisms containing incipient nucleus (Nucleoid) in their cells are called prokaryotes. Example : Bacteria, Nostoc (cyano bacteria/ B.G. Algae)

Question. Give one example for ciliated protozoans.
Ans : Paramecium.

Question. Which one is called malarial parasite?
Ans : Plasmodium.

Question. Name the disease caused by plasmodium.
Ans : Malaria.

Question. Which fungi act as a source of antibiotics?
Ans : Penicillium.

Question. What are saprophytic fungi?
Ans : The heterotrophic fungi which absorb soluble organic matter from dead substrates are called saprophytes.

Question. How are pores or holes all over the body of Porifera important?
Ans : The pores present all over the body of the organisms lead to a canal system that helps in circulating water throughout the body to bring in food and oxygen.

Question. If you are provided seeds of gram, wheat, rice, pumpkin, maize and pea. Classify these as Monocots/ Dicots.
Ans : Monocots : Wheat, Rice, Maize. Dicots : Gram, Pumpkin, Pea.

Question. What are hermaphrodites? Give two examples.
Ans : Hermaphrodites are the organisms that have both the sexes. Thus, it can produce both sperms and eggs and called hermaphrodites. Example : Sponges, earthworms.

Question. Give general characteristics of Porifera.
Ans :
(a) Animals with pores all over the body.
(b) Body is not well differentiated.
(c) Non-motile animals remain attached to solid support.
(d) Body is covered with hard outer skeleton. Example : Sponges.

Question. Give the characteristics of Arthropoda with 2 examples.
Ans :
(a) Arthropoda means jointed legs.
(b) Animals are bilaterally symmetrical and segmented.
(c) It has an open circulatory system.
(d) This is the largest group of animals.
Examples : Spider, scorpions, crabs, house flies.

Question. Give the characteristics of Ayes.
Ans : (a) Aves/birds can fly.
(b) Streamlined body.
(c) Hollow and light bones.
(d) Forelimbs are modified into wings.
(e) Warm-blooded animals, heart with four chambers.
(f) Egg laying animals.
(g) Beak present, teeth are absent.

Question. Write briefly about lichens.
Ans :
(1) Lichens are symbiotic close association of two different organisms such as algae and fungi.
(2) Algal component of lichen known as phycobiont which is photosynthetic in nature.
(3) Fungal component of living form is known as mycobiont which is non-photosynthetic, but helps in absorption of minerals, nutrients and water.
(4) Lichens are very good pollution indicator as they do not grow in polluted areas.
Question. Define species.
Ans : Species are organisms within genus with slight difference from other and capable of breeding and perpetuate.

Question. What is symbiotic relationship?
Ans : It is a relationship between two organisms in which both of them are benefitted, e.g., fungi gets food from blue-green algae and in return blue-green gets shelter (lichens).

Question. What is saprophytic nutrition?
Ans : The organisms that use dead and decaying organic matter as mode of nutrition is known as saprophytic nutrition.

Question. Name the plant amphibian.
Ans : Bryophyta, e.g. funaria.

Question. What are cryptogamae?
Ans : The plants with hidden reproductive organs are called cryptogamae, e.g., fern.

Question. Which divisions of the plant kingdom are called cryptogams? Why are they called so?
Ans : Thallophyta, Bryophyta and Pteridophyta divisions of plant kingdom are called cryptogamae. All these divisions have hidden reproductive organs.

Question. What are angiosperms?
Ans : Angiosperms are the group of plants with covered seeds. These are flowering plants.

Question. What is the meaning of triploblastic?
Ans : Animals which have three layers of cells : ectoderm, mesoderm and endoderm from which differentiated tissues can be made, e.g. tapeworm.

Question. What is bilateral symmetry?
Ans : Anything is said to have bilateral symmetry if its body have same design in left and right halves of the body.

Question. What do you mean by “cold-blooded animals”?
Ans : Cold-blooded animals are the animals that show the variation in their body temperature according to the surroundings, e.g., fish, amphibians, reptiles.

Question. Name a fish with skeleton made up of cartilage.
Ans : Shark.

Question. What is taxonomy?
Ans : The systematic study of identification, classification and naming of oraganisms is called taxonomy.

Question. Name the 2 kingdoms of classification?
Ans : (1) Plantae or Metaphyta
(2) Animalia or Metazoa

Question. What are Eukaryotes? Give an example of Eukaryotes?
Ans : Organisms which have well organized nuclei (True nucleus) are called Eukaryotes.
Example : Amoeba, mango, Man.

Question. What are multicellular organisms? Give an example for multi cellular organisms.
Ans : Organisms whose body is made up of many numbers of cells are called multicellular organisms.
Example : Spirogyra, Mango, Man.

Question. Who proposed five kingdom classification?
Ans : R.H. Whittaker (1969).

Question. What are Monerans?
Ans : Prokaryotic celled, unicellular and Autotrophic organisms.

Question. Name the kingdom which includes Bacteria.
Ans : Kingdom Monera.

Question. What are autotrophic bacteria? Give an example for autotrophic bacteria.
Ans : The bacteria which synthesize their own food from inorganic substances are called autotrophic bacteria.
Example : Nostoc, Anabaena.

Question. What are heterocysts?
Ans : The colourless specialized cells of nostoc filament meant for fixing atmospheric nitrogen are called heterocysts.

Question. What are chemosynthetic autotrophic bacteria?
Ans : The bacteria which oxidize inorganic substances like nitrate, nitrities and ammonia to release energy in the form of ATP are called chemosynthetic bacteria.

Question. What are mycoplasmas?
Ans : The smallest living organisms without cell walls and survive without oxygen are called mycoplasmas.

Question. What are planktons?
Ans : The microscopic organisms which floats on water are called planktons.

Question. Name the chemical component of cell wall of Diatoms.
Ans : Chitin.

Question. What are euglenoids?
Ans : The fresh water organisms found in stagnant water with protein rich particle in their cell wall are called euglenoids.

Question. What are plasmodium?
Ans : Aggregation of slime moulds under suitable conditions are called plasmodium, which may grow and spread over several feet. During unfavorable conditions they differentiate and follows fruiting bodies.

Question. Name parasitic protozoa.
Ans : Entamoeba, Plasmodium (Malarial parasite).

Question. Name the disease caused by Trypanosoma.
Ans : Sleeping sickness.

Question. What are the characteristic features of mammals?
Ans : Characteristic features of mammals :
(a) Body is covered with hair.
(b) Skin is provided with sweat and sebaceous glands.
(c) Heart is four-chambered.
(d) Fertilization is internal.
(e) Females have mammary glands to produce milk to nourish their young ones.
(f) External ear–pinna present.
(g) Eyes have eye lids.
(h) Warm-blooded.
(i) Respiration through lungs.

Question. What is the importance of heterotrophic bacteria?
Ans :
(1) Conversion of milk to curd.
(2) Antibiotic productions.
(3) N2 fixation in leguminous roots.
(4) Act as pathogen, causing diseases like cholera, typhoid, tetanus.
(5) Damage corps (citrus canker disease)
(6) Act as ‘Scavengers of nature’ by decomposing dead and decaying organic matter.

Diversity in Living Organisms Class 9 Science Notes