Class 9 Science Chapter 7 Diversity in Living Organisms

NCERT Class 9 Science Chapter 7 Diversity in Living Organisms, Question Answer to each chapter is provided in the list so that you can easily browse throughout different chapters Class 9 Science Chapter 7 Diversity in Living Organisms and select need one.

NCERT Class 9 Science Chapter 7 Diversity in Living Organisms

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Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. These solutions are part of SCERT All Subject Solutions. Here we have given SCERT Class 9 Science Chapter 7 Diversity in Living Organisms Solutions for All Subjects, You can practice these here.

Diversity in Living Organisms

Chapter – 7




Textbook Page No. 80

1. Why do we classify organisms?

Ans: The need to classify organisms arises because there are innumerable diverse species on this planet Earth ranging from a small microorganism (bacteria) to a large elephant. Therefore, we need a system to simplify our study of organisms present on the Earth and the name of that system is classification.

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

Ans. Three examples of the range of variations that we see in life around are mentioned below:

(i) Variety of living organisms in terms of size ranges from microscopic bacteria to tall trees of 100 metres. 

(ii) The colour, shape, and size of snakes are completely different from those of lizards. 

(iii) The life span of different organisms is also quite varied.

Textbook Page No. 82

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

(a) The place where they live. 

Ans. Do your self.

(b) The kind of cells they are made of. Why?

Ans. Do your self.

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

Ans. The primary characteristic on which the first division of organisms is made is the nature of the cell. A eukaryotic cell has membrane-bound organelles, including a nucleus, which allow cellular processes to be carried out efficiently in isolation from each other. Therefore, organisms which do not have a clearly demarcated nucleus and other organelles would need to have their biochemical pathways organised in very different ways. This would have an effect on every aspect of cell design. Further nucleated cells would have the capacity to participate in making a multicellular organism because they can take up specialised functions. Therefore, this is a basic characteristic of classification.

3. On what gases are plants and animals put into different categories? 

Ans. On the basis of their mode of nutrition, i.e. being able to produce one’s own food versus getting food from outside, plants and animals are put into different categories. Plants are autotrophs as they can prepare their own food by photosynthesis and animals are heterotrophs as they collect food from outside sources and from plants directly or indirectly.

Textbook Page No. 83

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

Ans. The organisms which have ancient cell organisations or body designs and have not modified much are called primitive or lower organisms. 

Advanced organisms are those which have acquired their particular body designs or cell organisations relatively recently. Primitive organisms are different from the so-called advanced organisms as they have simple body designs as compared to the more complex body designs of the advanced organisms. 

2. Will advanced organisms be the same as complex organisms? Why? 

Ans. Yes, advanced organisms may also be called complex organisms. Since there is a possibility that complexity in design will increase over evolutionary time, it may not be wrong to say that advanced organisms acquired more complex structure during evolutionary period for better survival.

Textbook Page No. 85

1. What is the criterion for classification of organisms as belonging to kingdom Monera or Protista? 

Ans. The criterion for classification of organisms as belonging to kingdom monera or pritista are mentioned below: 

(i) Unicellular organism.

(ii) Prokaryotic.

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

Ans. The kingdom that a multicellular, eukaryotic, photosynthetic organism belongs to is the kingdom Plantae.

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

Ans. In the hierarchy of classification, species will have the smallest number of organisms with a maximum of characteristics in common and kingdom will have the largest number of organisms.

Textbook Page No. 88

1. Which division among plants has the simplest organisms? 

Ans. Division-Thallophyta among plants has the simplest organisms.

2. How are pteridophytes different from the phanerogams?

Ans. The pteridophytes differents from the phanerogram are mentioned below:

Do not produces seeds .Produces seeds.
They have hiddens reproduction organs.They have well differentiate reproductive organs 
Primitive vasculars tissues are presents.Advance vasculars tissues are presents .

3. How do gymnosperms and angiosperms differ from each other?

Ans. The differences between gymnosperms and angiosperms are mentioned below: 

The plants of this bear naked seeds.The plants of this group contains seeds which develop inside an organ which ids further modified to became a fruit . 
Plant embryous in seeds contain many cotyledons.Plant embryos in seeds have structure called cotyedons.

Textbook Page No. 94

1. How do poriferan animals differ from coelenterate animals?

Ans. The poriferan animals differents forms coelenterate animals are mentioned below: 

Cellular level of organizatiomn present Tissue level of organization present 
A vast numbers of pores present on the body The singles opening present which severs as mouth as well s anus
Body is seddile and appendages absent .Body sessile as well as freely moving.appendages present in the time form tentacles.

2. How do annelid animals differ from arthropods?

Ans. The annelid animals different from arthropods are mentioned below: 

These are commonly called segmented worms.These are commonly called animals with jointed legs.
These contain true body cavity called coelom.The body cavity is present but it is blood flled and called haemoccel.
They breath through body surface (skine).They have different organs for breathing such as gills trachea book lung etc.

3. What are the differences between amphibians and reptiles? 

Ans. The differences between amphibians and reptiles are mentioned below:

They live both on land and water.They live either on the lnd water .
Body is converd with scales .They also have scales on their body .
They lay eggs in water.Water is not necessary fpr laying eggs.

4. What are the differences between animals 

belonging to the aves group and those in the mammalia group?

Ans. The differences between animals belonging to the aves groups and those in the mammalia group are mentioned below: 

Body is cover with feathers.Skin is covered with with hair.
Mammary glands are absent They have mammuary glands for the production of milk to nourish their their young ones.
Bones have air cavities.Bones are solidhard and filled with bone-marrow.


(Textbook Page No. 97)

1. What are the advantage of classifying organisms? 

Ans. The advantages of classifying organisms are mentioned below: 

(i) It serves as a base for other branches of life-science to study different groups of organisms from different areas of science such as ecology, biogeography, genetics, behavioural sciences, etc. 

(ii) It also helps us to identify various pathogens, parasites, pests, disease vector, etc.

(iii) It simplifies the way of studying diverse life forms. 

(iv) It reveals before us a systematic scheme of position of all organisms at a glance.

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

Ans. Two characteristics to be used for developing a hierarchy in classification, one character must be dependent on another, then only the first one can be placed under the other.

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

Ans. Biologist Robert H. Whittaker proposed the five kingdom classification in 1959. 

The basis of this five kingdom classification are:

(i) The prokaryotic versus eukaryotic structure of cell. 

(ii) The cell organisation is whether unicellular or multicellular.

(iii) Cells have cell wall or not.

4. What are the major divisions in the plantae? What is the basis for these divisions?

Ans. The basis for the classification of plantae in five divisions are mentioned below:

(i) Whether the plant body is well-differentiated or simply a thallus. 

(ii) Whether the differentiated plant body has special tissue (vascular tissue) for water and mineral transport. 

(iii) Whether the plant bears seeds or not.

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

Ans. The criteria for decidng division in plants are different from the criteria for deciding the sub-groups among animals because the basic designs of their body is different. The body design of the two groups is baseed on the need to make their own food in case of plants and to acequire it from external source in case of animals. The other characteristics such as presence of absence of skeleton, etc. are used to make sub-groups among animals.

6. Explain how animals in vertebrate are classified into further subgroups. 

Ans. Vertebrates are classified according to several criteria like an exoskeleton, respiratory organs, method of giving birth, number of chambers in heart, mode of living, etc. Animals in Vertebrata are mainly classified into five classes: – Pisces: This class consists of fishes that are aquatic, cold-blooded animals.

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