Chapter 19 Classification of Living Organisms

NIOS Class 10 Science Chapter 19 Question Answers

INTEXT QUESTIONS 19.1

1. What does biodiversity mean?

Ans: The various living beings living on earth constitute biodiversity.

2. Define (i) species, (ii) biosphere, (iii) ecosystem.

Ans:

• Species: A Group of very similar organisms that can interbreed to produce fertile offspring.
• Biosphere: It is the physical part of the Earth on which organisms can survive.
• Ecosystem: The definite geographical region in which various species of organisms live and interact with each other and the physical environment.

3. Name the three levels of biodiversity.

Ans: Ecological diversity, species diversity, and genetic diversity.

4. What is meant by biodiversity hotspots?

Ans: Hot spots are those areas of a country where some typical plants and animals (organisms) are exclusively present.

INTEXT QUESTIONS 19.2

1. What is meant by classification?

Ans: Grouping of organisms in biodiversity according to similarities and differences is termed classification. Classification shows evolutionary relationships between organisms and is also termed Systematics.

2. How has classification made study of diversity possible?

Ans: Classification divides the millions of identified organisms into groups and subgroups, making the study of their enormous diversity possible.

3. Name the three domains into which all the organisms of the world are categorised

Ans: Archaebacteria, Eubacteria, and Eukarya

4. Name the five kingdoms of life and mention the three features on which this classification is based.

Ans: Monera, Protoctista (Protista), Fungi, Plantae, and Animalia

5. Study the table 19.2 on kingdoms of life and fill in the names of kingdom at A to E in the flow chart given below :

Ans: A= Monera, B= Protoctista, C= Fungi, D=Plantae, E= Animalia

INTEXT QUESTIONS 19.3

1. Find out the scientific name of the following :

Frog, cat, China rose, onion.

You may get them from someone in your neighbourhood who knows Biology, or from the internet, or some Biology book.

Ans: 

• Frog: Rana tigrina
• Cat: Felis domestica
• China rose: Hibiscus rosa sinensis
• Onion: Allium cepa

2. In the following table, fill in plus (+) for present and minus (-) for absent to show the difference between plants and animals. 

Features	Plant	Animal
Chlorophyll
Muscles
Nerves
Locomotion
Leaves and Roots
Mouth and Anus

Ans:  

Features	Plant	Animal
Chlorophyll	+	–
Muscles	–	+
Nerves	–	+
Locomotion	–	+
Leaves and Roots	+	–
Mouth and Anus	–	+

3. See the pictures of the two arthropods shown below. Mark one similarity and one difference

Ans: 

• Similarity = Jointed legs/body divided into head, thorax, and abdomen.
• Differences = No.of pairs of legs

4. Which out of ABCD is

a. Fungus 

b. Fern 

c. Moss 

d. Alga

Ans: A= Algae, B= Moss, C=Fungus, D=Fern

5. Write the name of the phylum to which each of the animals shown in the pictures below belongs.

Ans: 

a. Earthworm – Annelida

b. Pila – Mollusca

c. Round worm – Aschelminthes

d. Hydra – Cnidaria

e. Sponge – Porifera

f. Starfish – Echinodermata

g. Fish – Chordata

h. Humans – Chordata

TERMINAL EXERCISES

1. Define biodiversity. Mention its three levels and briefly explain them.

Ans: The enormous variety of organisms is termed biodiversity (bios means life and diversity means variety).  Its three levels are ecological, species and genetic diversity. 

2. What are the global and Indian patterns of biodiversity? What do you mean by a ‘hot spot’ of diversity?

Ans:   As per the global pattern of biodiversity, the entire world is divided into six biogeographic regions. The organisms found in these regions are well-adapted to the local climate. Certain kinds of organisms are common to all regions, while some are restricted to certain regions only. e.g. elephants are found only in Asia and Africa and nowhere else in the world. Grass is found all over the world.

India has two biodiversity ‘hotspots’—the Western Ghats and North-Eastern regions (including the Eastern Himalayas). ‘Hotspots’ are regions of the world where many different kinds of organisms live. Many of these organisms are not found elsewhere, e.g. Many species of frogs live only in the Western Ghats of India.

3. Name the three domains of life and state one distinguishing feature of each.

Ans:   The three domains of life are, 

• Archaebacteria are thermophilic or heat-loving bacteria that live in high-temperature vents.
• Eubacteria are single-celled organisms without a well-developed nucleus.
• Eukarya are all other organisms with a well-formed nucleus in their cell/cells. (Eu: true; Karyon: nucleus)

4. Name the five kingdoms of life and state one feature of each of the kingdoms which differs from that of the others.

Ans:   The five kingdoms of life are as follows. 

• Monera: Single-celled, no well-formed nucleus (Prokaryotes)
• Protoctista or Protista: Single-celled with a well-formed nucleus (Eukaryotes)
• Fungi: Eukaryotes, multicelled saprotrophs
• Plantae: Eukaryotes, multicelled, autotrophs
• Animalia: Eukaryotes, multicelled, heterotrophs

5. Give an account of the classification of Kingdom Plantae into its divisions. Cite examples.

Ans:   The Kingdom Plantae is divided into 4 divisions. 

• Algae: (No special roots, stem, or leaves) e.g,. the algae
• Bryophyta: Root-like hyphae but no true roots, e.g., Liverworts and mosses.
• Pteridophyta: True roots, underground stem, spore-bearing leaves. e.g. Ferns
• Spermatophyta: Seed-bearing plants. It is further divided into Gymnosperms and Angiosperms.
  • Gymnosperms: No flowers, seeds naked and not enclosed in fruit e.g. Pine, Juniper.
  • Angiosperms: Flowering plants, fruits bear seeds. All flowering plants

6. State the difference between chordates and non-chordates.

Ans:   The presence or absence of a notochord is the main difference between chordates and non-chordates. Notochord is a solid rod-like tissue in the embryo which becomes the vertebral column or backbone in vertebrates. Chordates have a notochord at some stage of life, while in non-chordates, it is completely absent. 

7. Name the phyla to which the following belong: wolf, earthworm, sponge, jellyfish, sparrow, butterfly, starfish, snail, tapeworm, round worm

Ans:   

• Wolf: Chordata
• Earthworm: Annelida
• Sponge: Porifera
• Jellyfish: Cnidaria
• Sparrow: Chordata
• Butterfly: Arthropoda
• Starfish: Echinodermata
• Snail: Mollusca
• Tapeworm: Platyhelminthes
• Round Worm: Nematoda

8. To which class of chordates do the following belong? Justify your inclusion into the class by stating any one characteristic feature. Crow, lion, cobra, flying frog, shark, freshwater fish.

Ans:   

• Crow: Class Aves- They have light bones and live an aerial mode of life.
• Lion: Class Mammalia- Presence of mammary glands for producing milk for young ones.
• Cobra: Reptilia- Body covered with scales.
• Flying Frog: Amphibia- Adapted to both land and water life.
• Shark: Chondrichthyes- Has skeleton made of cartilage.
• Freshwater Fish:  Osteichthyes- Have gills for breathing.

9. Write three sentences on why we need to classify and give scientific names to organisms.

Ans:   A Scientific name has several advantages and constitutes the specific identity of the specific organism.

• It is understood all over the world.
• It consists of two words; the name of the Genus to which it belongs begins with a capital letter, and the name of the species to which it belongs begins with a small letter, e.g., cat is Felis domestica, where Felis is the genus name and domestica the name of the species.
• A scientific name is always written either in italics or underlined.
• Having two names is the Binomial system of nomenclature (naming) introduced by the Swedish naturalist of the 18th century, Carolus Linnaeus.

10. Why does biodiversity need to be conserved?

Ans: We must all strive to conserve biodiversity because organisms are interdependent and together maintain a balance in nature. The flora and fauna of our nation is our heritage. We have to conserve our heritage.

11. State three ways by which biodiversity may be conserved?

Ans:   

• Spread awareness regarding the dwindling biodiversity and the necessity of conserving its habitats.
• Form a group with your friends and organise painting and chart-making competitions, essay writing, declamation, and slogan writing contests on the conservation of biodiversity.
• Hold debates on issues of biodiversity conservation in your neighbourhood.

12. List 10 ways in which organisms help each other survive in nature. What message can you derive from their interdependence?

Ans:   

1. The bacteria and fungi recycle organic matter to feed diverse organisms.
2. Algae and plants trap solar energy for photosynthesis and produce food for all living creatures. Insects and bats pollinate flowers. Animals also disperse seeds.
3. Ecosystems such as forests, deserts, aquatic bodies, and wetlands sustain their own typical biodiversity, some of which are part of their unique food chains and food webs.

13. Why have some plants and animals become endangered? State at least five human activities as causes.

Ans:  The growing human population and the subsequent excessive demands on environmental resources for food and energy, is a huge reasons that have caused several plants and animals to become endangered. 

• The generation of a huge amount of waste causes the extinction of several plants.
• Fish and molluscs are overexploited as human food.
• Poaching for fur and ivory leads to animal extinction. Illegal cutting of forest trees, such as sandalwood.
• Illegal trade of birds.
• Monkeys and tigers are exploited for making traditional medicines.

14. Write in a paragraph on “what would happen if living beings did not have scientific names and were not grouped.” Mention at least five consequences.

Ans:  Scientific names are crucial for identifying plants and animals and assigning them to their respective class or orders based on their characteristics. Sometimes it also gives a hint at their respective location. Without scientific names, there could be consequences that can affect various aspects, as given here. 

• There are millions of plants and animals identified across the world, and each country or region has a different name for the same organism.
• Without a unified scientific name, they are difficult to identify, communicate, or conduct advanced studies of these organisms.
• Without scientific names, tracking and conserving various organisms or plants will be impossible, as there will be a lack of proper organisation.
• It will be impossible to study the evolution and other historical data of each species or organism.
• Scientific names provide a structure and organised form to the various data regarding each species. Without such consolidated data, discoveries regarding them will be lost or will not make any progress.

15. You find some boys pelting stones at a monkey sitting on a tree. Write five sentences which can dissuade those boys.

Ans:   Write on your own.