NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms Questions and Answers

Discover a comprehensive collection of questions and answers on Diversity in Living Organisms, specifically tailored for Class 9 students. This resource provides a deep understanding of the chapter, covering various aspects such as classification, characteristics, and interrelationships among different living organisms. With step-by-step explanations and accompanying images, these answers will help you grasp the concepts effectively. Whether you are studying for exams or seeking a better comprehension of the subject, this compilation of NCERT solutions offers a valuable resource. Explore the fascinating world of living organisms and enhance your knowledge with this essential guide for Class 9 Science students.

Diversity in Living Organisms Questions and Answers Class 9

Page : 80      

Q1. Why do we classify organisms?

Ans. There are several varieties of living organisms on the earth. It is not easy to study all of them one by one.

so, we place them in different groups based on similarities and differences. whic makes the study easy and systematic.

Q2. Give three examples of the range of variations that you see in life-forms around you.

Ans. The examples of the range of variations in different life forms are:

  1. Variations in size: small bacteria and big redwood trees.
  2. Variations in life span: insects live a few hours. some trees live for thousands of years.
  3. Variations in body colours: some are colourless while some are colourful.

Page : 82

Q1. Which do you think is a more basic characteristic for classifying organisms?

(i) The place where they live.

(ii) The kind of cells they are made of and why?

Ans. The more basic characteristic for classifying organisms is the kind of cells they are made of because that helps organisms to survive and multiply.

Q2. What is the primary characteristic on which the first division of organisms is made?

Ans. Cells have membrane-bound organelles or nuclei and the nature of cells are the primary characteristics on which the first division of organisms is decided.

Q3. On what bases are plants and animals put into different categories?

Ans. Plants and animals are put into different categories on the basis of their mode of nutrition and the presence or absence of cell walls.

NCERT Solutions for Class 9 Science

Page : 83

Q1. Which organisms are called primitive and how are they different from the so-called – advanced organisms?

Ans. Primitive Organisms have a simple cellular structure and no division of labour. also, ancient body designs are called primitive.

Advanced organisms, Their body has a particular design and have millions of cells in their body. There are different organs and organ systems for different biological functions.

Q2. Will advanced organisms be the same as complex organisms? why?

Ans. Yes, the advanced organisms will be the same as complex organisms. This is because advanced organisms mean a greater degree of evolution, which leads to more complex body designs.

Page : 85

Q1. What is the criterion for classification of organisms as belonging to the kingdom-Monera and Protista?

Ans. The criteria for the classification of organisms belonging to the Kingdom of Monera and Protista is the presence or absence of a well-defined nucleus. Monera has no nuclear membrane, while Protista shows a well-defined nucleus.

Q2. In which kingdom will you place an organism, which is single-celled, eukaryotic and photosynthetic?

Ans. This organism belongs to : Kingdom – Protista.

Q3. In the hierarchy of classification, which grouping will have the smallest number of organisms with a maximum of characteristics in common and which will have the largest number of organisms?

Ans. In the hierarchy of classification, the species is the grouping, which has the smallest number of organisms.  

The grouping which has the largest number of organisms is the kingdom.

Page : 88

Q1. Which division among plants has the simplest organisms?

Ans. Thallophyta of plant kingdom.

Q2. How are pteridophytes different from the phanerogams?


1. They have naked embryos.1. They have covered embryos.
2. They have hidden reproductive organs. 2. They have well-differentiated reproductive tissues.
e.g. ferns. e.g. pines, mango etc.

Q3. How do the gymnosperm and angiosperms differ from each other?


1. Seeds are naked.1. Seeds are covered.
e.g. deodar and Pinus.e.g. pea and wheat

Page : 94

Q1. How do poriferan animals differ from coelenterate animals?


1. These organisms have holes in their body.1. The body has a single opening.
2. The body shows a cellular level of organisation2. The body shows tissue level of organisation.
3. These are non-motile.3. These are motile.

Q2. How do annelid animals differ from arthropods?


1. The body is segmented.1. The body is segmented into rings.
2. No compounded eyes.2. Compounded eyes are present.
3. Locomotion by paired lateral appendages only.3. Locomotion by paired appendages, but some animals have wings also.

Q3. What are the differences between amphibians and reptiles?


1. They have lungs or gills.1. They have only lungs.
2. They have a non-scaly exoskeleton.2. They have a scaly exoskeleton.
3. They can jump.3. They Crawl only.
4. They can live on both water and land.4. They live only on land.
5. e.g. frog, toad, etc 5. snakes, crocodiles etc.

Q4. What are the differences between animals belonging to the Aves group and those in the Mammalia group?


Aves Mammalia
1. They have beak.1. They have teeth.
2. Their body is covered with feathers.2. Their body is covered with hairs.
3. Bones are hollow.3. Bones are hard and solid.
4. They lay eggs.4. They produce young ones.
5. Body is streamlined. 5. Their body is not streamlined.


Q1. What are the advantages of classifying organisms?

Ans. Advantages of classification of organisms:

  1. It makes the study of a wide variety of organisms easy.
  2. It helps in the study of patterns of evolution.
  3. It gives information regarding the diversity of plants and animals.

Q2. How would you choose between two characteristics to be used for developing a hierarchy in classification?

Ans. For developing a hierarchy in classification, we choose :

  1. the cells occur individually or in groups.
  2. presence of mammary glands keep them under mamaliya.

Q3. Explain the basis for grouping organisms into five kingdoms.

Ans. Following criteria are the basis of classification of the organisms:

  1. Mode and source of nutrition (autotrophic and heterotrophic).
  2. Number of cells (prokaryotic or eukaryotic).
  3. Presence or absence of cell wall

Q4. What are the major divisions in the kingdom Plantae? What is the basis for these divisions?

Ans. Major divisions of kingdom-Plantae are:

(i) Thallophyta

(iii) Pteridophyta

(ii) Bryophyta 

(iv) Gymnosperms

(v) Angiosperms

Basis of these divisions in Plantae are:

  1. ability to bear seeds.
  2. Seeds are covered or not.
  3. Is the body of the plant is well- differentiated or not?
  4. Tissues for the transportation of water and other substances are present or not.

Q5. How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?

Ans. The criteria for deciding divisions in plants is based on whether they have the ability to bear seeds or not. Gymnosperms and angiosperms are further segregated based on whether seeds are covered or not. 

Animals are classified based on layers of cells, symmetry, presence or absence of notochord, and body cavity. Further higher in the hierarchy, animals are classified based on the presence or absence of features, like the presence or absence of four legs.

Q6. Explain how animals in Vertebrata are classified into further subgroups.

Ans. Characteristics for classifying quality data into further subgroups are:

(a) Pices: They breathe through gills and lay eggs in water. they have an endoskeleton of bones and catalyser exoskeleton is made up of scales.

(b) Reptilia: These are crawling animals. Skin is hard to withstand extreme temperatures. They lay eggs outside of water and their skeleton is made up of scales.

(c) Amphibia: These are water and land animals. Can breathe oxygen through gills/lungs.

(d) Aves: flying capability is present and forelimbs are modified into wings to assist in flying. bones are hollow and light. Beaks are present. Body is covered with feathers.

(e) Mammalia: Mammary glands present to nurture young ones. Skin is covered with hair. give birth to young ones.

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