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Samacheer Kalvi 7th Science Books Basis of Classification

Science : Term 2 Unit 5 : Basis of Classification


I. Choose the correct answer.

1. The following characteristics are essential for classification.

a. Similarities

b. Differences

c. Both of them

d.  None of them

Answer: (e) Both of them

2. Approximately ____________ species of living organisms found in the earth.

a. 8.7 million

b. 8.6 million

c. 8.5 million

d. 8.8 million

Answer: (a) 8.7 million

3. The largest division of the living world is __________

a. Order

b. Kingdom

c. Phylum

d. Family

Answer: (b) Kingdom

4. Who proposed the five kingdom of classification?

a. Aristotle

b. Linnaeus

c. Whittakar

d. Plato

Answer: (c) Whittakar

5. The binomial name of pigeon is _________

a. Homo sapiens

b. Rattus rattus

c. Mangifera indica

d. Columbo livia

Answer: (d) Columbo livia

II. Fill in the blanks.

1. Gaspard Bauhin in 1623, introduced the binomial nomenclature.

2. Species is the basic unit of classification.

3. Fungi are non- green and non-photosynthetic in nature.

4. The binomial name of onion is Allium sativum.

5. Carolus Linnaeus is known as the Father of Modern Taxonomy.

III. True (or) False. If false write the correct answer.

1. Classification helps to know the origin and evolution of an organism. (True)

2. Fishes are aquatic vertebrates. (True)

3. In the year 1979, Five kingdom classification was proposed. (False)

In the year 1969, Five kingdom classification was proposed.

4. True nucleus is seen in prokaryotic cell. (False)

True nucleus is seen in Eukaryotic cell.

5. Animal cells have cell wall. (False)

Animal cells do not have cell wall Plant cells have cell wall.

IV. Match the following.

1. Monera –   Moulds

2. Protista –    Bacteria

3. Fungi –      Neem

4. Plantae –    Butter fly

5. Animalia –  Euglena

Answer :

1. Monera  – Bacteria

2. Protista  – Euglena

3. Fungi      – Moulds

4. Plantae    – Neem

5. Animalia – Butterfly

V. Assertion and Reason Questions

1. Assertion: Binomial name is the universal name and contains two names.

Reason : It was first introduced by Carolus Linnaeus

a. Assertion is correct, Reasoning is correct

b. Assertion is correct, Reasoning is incorrect

c. Assertion is incorrect Reasoning is correct

d. Assertion and Reasoning are incorrect

Answer: b. Assertion is correct, Reasoning is incorrect

2. Assertion: Identification, assortment and grouping are essential for classification

Reason : These are basic steps of taxonomy

a. Assertion is correct, Reasoning is correct

b. Assertion is correct, Reasoning is incorrect

c. Assertion is incorrect Reasoning is correct

d. Assertion & Reasoning is incorrect

Answer: a. Assertion is correct, Reasoning is correct

VI. Give very short answer

1. What is classification?

The method of arranging the organisms into groups is called classification. When we classify things we put them into groups based on their characteristics.

2. List out the five kingdoms classification

1) Monera

2) Protista

3) Fungi

4) Plantae

5) Animalia

3. Define – dichotomous key

Dichotomous key is a tool used to classify organisms based on their similarities and differences.

4. Write two examples of Monera.

1) Bacteria

2) Blue green algae

5. What is binomial nomenclature?

Binomial nomenclature is a universal system of naming organisms. It contains two names. The first name of binomial is genus name and the second name is species name.

6. Write the binomial name of a) Human being b) Paddy

a) Human being – Homo sapiens

b) Paddy – Oryza sativa

7. Write two features of protista

1) It includes unicellular and a few simple multicellular eukaryotes.

2) The plant-like protists are photosynthetic.

VII. Give short answer

1. Write the levels of classification.

The classification of living things include seven levels. They are 1. kingdom, 2. phylum, 3. classes, 4. order, 5. families, 6. genus and 7. species.

2. Differentiate plantae and animalia

Planatae (plants) are multicellular eukaryotes that carry out photosynthesis. Reserve food materials are starch and lipids in the form of oil or fat. Plant cells have cell wall and specialized functions, such as photosynthesis, transport of materials and support.

Animalia (animals) are multicellular, eukaryotic and heterotrophic animals. Cells have no cell wall. Most members of the animal kingdom can move from place to place.

3. Write any two merits of Five Kingdom classification.

❖ This system of classification is more scientific and natural.

❖ This system of classification clearly indicates the cellular organization, mode of nutrition, and characters for early evolution of life.

❖ It is the most accepted system of modern classification as the different groups of organisms are placed phylogenetically.

❖ It indicates gradual evolution of complex organisms from simpler one.

VIII. Give answer in Detail

1. Explain about five kingdom classification

Kingdom Animalia: Animalia (animals) are multicellular, eukaryotic and heterotrophic animals. Cells have no cell wall. Most members of the animal kingdom can move frojn place to place. Eg. Invertebrates like sponges, hydra, flatworms, round worms, insects, snails, starfishes. Vertebrates like Fish, amphibians, reptiles, birds, and mammals including human beings belong to the kingdom Animalia.


2. Write short notes on – Binomial Nomenclature.

Gaspard Bauhin in 1623, introduced naming of organisms with two names which is known as Binomial nomenclature, and it was implemented by Carolus Linnaeas in 1753. He is known as ‘Father of Modern Taxonomy’.

Binomial nomenclature is a universal system of naming organisms. As per this system, each organism has two names – the first is the Genus name and the second is the Species name. Genus name begins with a capital letter and Species name begins with a small letter.

Example: The nomenclature for onion is Allium sativum. Genus name is Allium, species name is sativum.

3. Give an account on the classification of invertebrates with few general features and examples.

General Characters

1. Microscopic unicellular, pseudopodia, flagella and cilia for locomotion, reproduce by fission or conjugation.

Division: Phylum Protozoa

Eg. Amoeba, Euglena and Paramoecium

2. Multicellular organisms with holes in the body. Skeleton formed of spicules, asexual and sexual reproduction.

Division: Phylum Porifera

Eg. Leucosolenia, Spongilla, Sycon.

3. Multicellular organisms Diploblastic, sessile or free swimming, solitary or colonial, asexual and sexual reproduction

Division: Phylum Coelenterata

Eg. Hydra, Sea anemone, Jelly fish, Corals.

4. Acoelomates, parasites inside the body of animals and human beings, mostly hermaphrodite (bisexual).

Division: Phylum Platyhelminthes

Eg. Planaria, Liver fluke, Blood fluke, Tapeworm

5. Unsegmented body, mostly parasites in human beings and animals, causing diseases, asexual reproduction.

Division: Phylum Aschelminthes or Nematoda

Eg. Ascaris lumbricoides

6. Triploblastic, segmented body, mostly hermaphrodite, (bisexual and unisexual)

Phylum Annelida

Eg. Earthworm, Nereis, Leech.

7. Segmented body, thick chitinous cuticle forming an exoskeleton, paired and jointed legs, unisexual exhibits sexual dimorphism  

Division: Phylum Arthropoda

Eg. Crab, Prawn, Millipede, Insects, Scorpion, and Spider.

8. Soft bodied, unsegmented, muscular head, foot and visceral mass, mantle, a calcareous shell, sexual reproduction.

Division: Phylum Mollusca

Eg. Cuttle Fish, Snail, Octopus.

9. Exclusively marine, spines and spicules over the body, water vascular system, tube feet, for feeding, respiration and locomotion, sexual reproduction

Division: Phylum Echinodermata

Eg. Starfish, Sea – Urchin, Brittle star, Sea cucumber and Sea-lily


Which kingdom has saprophytic, parasitic and symbiotic nutrition. Why?

‘Fungi’ has the mode of nutrition – saprophytic, parasitic and sometimes symbiodic.

Parasites grow upon living hosts, e.g : powdery mildews. Saprophytes live on dead and decayed things, e.g Mucor. Symbiotic association is between a green plant and a fungus. The plant makes food by photosynthesis. It supplies the food to the fungus. The fungus in turn supplies the plant with water and mineral nutrients taken from the soil. e.g Mycorrhiza.

X. See the Diagram and write the kingdom :

Pictures of some living organisms are given below. Identify the kingdom to which each of these belong and write the kingdom name in the blanks provided.

Pictures of some living organisms are given below. Identify the kingdom to which each of these belong and write the kingdom name in the blanks provided.

(a) Plantae            (b) Protista 

(c) Monera            (d) Animalia          (e) Fungi

Student Activities


Aim : To sort out a box of given buttons and classify them into different types. Materials Required :  A box full of different types of buttons.


1. Take a box of given buttons.

2. Work in small groups of three or four and classify the buttons based on the following classification criteria.

i. Shape

ii. Buttons with four holes

iii. Buttons with two holes.

iv. Colour

3. Identify other features that can be used to sort out buttons into different groups.


Fill up the blanks with the suitable organisms

1. Vertebrates mandog and tiger.

2. Invertebrates earthwormcrab and snail.

3. Name the vertebrates with wings parrothen.

4. Name the invertebrates with wings butterflyhousefly.

5. Name the invertebrates with segmented legs crablobster.

6. Name the invertebrates with Jointed legs scorpionspider.

7. Name the warm blooded vertebrates man, bear.

8. Name the cold blooded vertebrates fish, crocodile.

9. Name the vertebrates with lungs respiration goatdog.

10. Name the animal with beak eagle.


Given table shows the name of the phylum and its characteristic features. Write name of the animals belonging to the respective phylum.

Phylum   :    Characters   :    Example

Porifera   :   Pore bearers   :     Spongilla

Coelenterata :    Gastro vascular cavity : Hydra

Platyhelminthes  : Flame cells     :     Tapeworm

Aschelminthes  :  Thread like worms : Ascaris lumbricoides

Annelida    :   Body is segmented   :    Earthworm

Arthropoda   :   Have jointed legs  :   Crab

Mollusca   :  Soft bodied with shells  :  Snail

Echinodermata : Spines on the skin  :   Starfish

Chordata    :    Have backbone   :     Man


Field trip to sanctuaries / zoo should be arranged. Students are guided to observe the animals and explain about the feature of animals how they are protected and maintained in the zoo. Note the displayed names of the plants and animals. Discuss your observation in the class

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