NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms, contains solutions to various questions in Exercises for Chapter 7. Diversity in Living Organisms Class 9 NCERT Solutions have been explained in a simple and easy to understand manner. NCERT Solutions for Class 9 help to check the concept you have learned from detailed classroom sessions and the application of your knowledge.
| Category | NCERT Solutions for Class 9 |
| Subject | Science |
| Chapter | Chapter 7 – Diversity in Living Organisms |
Download NCERT Solutions for Class 9 Science Chapter 7 – Diversity in Living Organisms
NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms Question Answers
1. Why do we classify organisms?
Answer:
There is a vast variety of living organisms on 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. Classification of organisms makes their study systematic, easy and quick.
2. Give three examples of the range of variations that you see in life-forms around you.
Answer:
Examples of range of variations in life forms are:
- Variation in size- Bacteria are microscopic organisms while on the other hand, blue whale and red wood trees are giant living creatures.
- Variation in life span- Insects like fruit flies live for a few hours while some trees live for years.
- Variation in body color- Some organisms for example, worms are colourless while certain birds, flowers, etc are colourful.
NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms – Intext Questions: Page 82
1. Which do you think is a more- basic characteristic for classifying organisms?
(a) the place where they live.
(b) the kind of cells they are made of. Why?
Answer:
The more- basic characteristic for classifying organisms is (b) the kind of cells they are made up of i.e. are they prokaryotic or eukaryotic.
It is misleading to classify organisms based on their habitat as many different types of organisms may live in the same place but they do not belong to the same group. For example: whales, octopus, corals, starfish, etc live in the sea but they are different from each other.
2. What is the primary characteristic on which the first division of organisms is made?
Answer:
The primary characteristic on which the first division of organisms is made on the basis that whether the organisms are prokaryotic or eukaryotic.”
3. On what bases are plants and animals are put into into different categories?
Answer:
Plants and animals are put into different categories based on their mode of nutrition. Plants are autotrophs while animals are heterotrophs. Their body designs are also different. Plants possess a cell wall while animals don’t.
Page 83
1. Which organisms are called primitive and how are they different from the so-called – advanced organisms?
Answer:
The organisms that came into existence earlier are referred to as “primitive” while the organisms the came into existence later are called “advanced”. Primitive organisms have simple body structure while advanced organisms have complex body structure and organization.
2. Will advanced organisms be the same as complex organisms? Why?
Answer:
Yes, advanced organisms will be the same as complex organisms. This is because complexity of organisms have increased over evolutionary time.
Diversity in Living Organisms Question Answers: Page 85
1. What is the criterion for classification of organisms as belonging to kingdom Monera or Protista?
Answer :
The organisms which do not possess well-defined nucleus, organelles, and multicellular body design are grouped under Kingdom Monera while the organisms which are unicellular and eukaryotic are grouped under the kingdom Protista.
2. In which kingdom will you place an organism which is single-celled, eukaryotic and photosynthetic?
Answer:
Kingdom – Protista
3. 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?
Answer:
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
NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms Page 88
1. Which division among plants has the simplest organisms?
Answer:
The organisms belonging to the division THALLOPHYTA are the simplest among the plants.
2. How are pteridophytes different from the phanerogams?
Answer:
The plants belonging to pteridophytes do not produce seeds while those belonging to gymnosperms produce seeds.
3. How do gymnosperms and angiosperms differ from each other?
Answer:
The gymnosperms bear naked seeds i.e. seeds are not enclosed within fruits while angiosperms have seeds inside fruits.
Diversity in Living Organisms NCERT Solutions Class 9 Science – Intext Questions: Page 94
1. How do poriferan animals differ from coelenterate animals?
Answer:
| PORIFERA | COELENTERATE |
| They have cellular level of organization | They have tissue level of organization. |
| These organisms do not have division of labour. | They possess division of labour. |
| Ex. Spongilla, Euspongia | Ex. Hydra, corals |
2. How do annelid animals differ from arthropods?
Answer:
| ANNELIDA | ARTHROPODA |
| Animals are segmented both externally and internally. | Animals are segmented only externally. |
| Exoskeleton absent. | Exoskeleton present. |
| Ex. Earthworms, Leech | Ex. Prawn, spider |
3. What are the differences between amphibians and reptiles?
Answer:
| AMPHIBIANS | REPTILES |
| They have a slimy skin | They have a exoskeleton of scales |
| They mostly lay eggs inside water. | They lay eggs outside water. |
| Their larvae have gills | Their larvae do not have gills |
| Ex. Frog, tadpole | Ex. Lizard, snakes |
4. What are the differences between animals belonging to the Aves group and those in the mammalia group?
Answer:
| AVES | MAMALLIA |
| It includes birds which are oviparous
i.e. lay eggs |
It includes animals which give birth to their young ones i.e.are viviparous. |
| Body is covered by feathers and they possess a beak. | Feathers and beak are absent. |
NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms – NCERT Exercises : Page 97
1. What are the advantages of classifying organisms?
Answer:
i. Classification of organisms facilitates their identification and makes their study convenient.
ii. It gives information about organisms which do not occur in one’s locality.
iii. It reveals evolutionary trends.
iv. It gives data regarding inter-relationship between different organisms.
2. How would you choose between two characteristics to be used for developing a hierarchy in classification?
Answer:
For developing a hierarchy in classification, we choose the more
fundamental characteristics for making the broadest divisions. Then, we should pick up next set of characteristics for making sub-groups.
3. Explain the basis for grouping organisms into five kingdoms.
Answer:
Basis of classification:
i. Complexity of cell structure: Two groups are formed- (I) organisms having prokaryotic cell structure or (II) those having eukaryotic cell structure.
ii. Number of cells: Organisms may be unicellular or multicellular.
iii. Mode of nutrition: Mainly two categories: autotrophic or heterotrophic
iv. Cell wall: Presence or absence of cell wall divides the organisms into groups.
4. What are the major divisions in the Plantae? What is the basis for these divisions?
Answer:
Major divisions in Kingdom plantae are:
- Thallophyta
- Bryophyta
- Pteridophyta
- Gymnosperms
- Angiosperms
Basis of these divisions are:
- Whether the plants possess well-differentiated body or not; it seperates thallophytes that have thallus like body.
- Presence or absence of vascular tissues; bryophytes lack these tissues.
- Ability to bear seeds; pteridophytes do not have seeds.
- Whether seeds are naked or enclosed in fruits; gymnosperms bear naked seeds.
5. How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?
Answer:
The criteria for deciding divisions in plants is different from the criteria for deciding the subgroups among animals because their basic body design is different. The body design of the two groups is based on the need to make their own food in case of plants and to acquire it from external source in case of animals. Other characteristics such as presence or absence of skeleton, etc is used to classify animals.
6. Explain how animals in Vertebrata are classified into further subgroups.
Answer:
The major characteristics used to study vertebrata are-
- Kind of exoskeleton and endoskeleton
- The kind of respiratory organs
- The method of reproduction
Based on the above characteristics, vertebrates are classified into following groups:
- Pisces- Exoskeleton of scales; endoskeleton of cartilage or bone; breathing through gills
- Amphibia- Skin slimy; breathing through gills only in larva
- Reptilia- Exoskeleton of scales; laying eggs outside water
- Aves- exoskeleton of feathers, lay eggs, flight possible
- Mammalia- Exoskeleton of hairs; give birth to their young ones.
Topics Covered in Diversity in Living Organisms Class 9 Science
- What is the Basis of Classification?
- Classification and Evolution
- The Hierarchy of Classification Groups
- MONERA
- PROTISTA
- FUNGI
- PLANTAE
- ANIMALIA
- Plantae
- THALLOPHYTA
- BRYOPHYTA
- PTERIDOPHYTA
- GYMNOSPERMS
- ANGIOSPERMS
- Animalia
- PORIFERA
- COELENTERATA (CNIDARIA)
- PLATYHELMINTHES
- NEMATODA
- ANNELIDA
- ARTHROPODA
- MOLLUSCA
- ECHINODERMATA
- PROTOCHORDATA
- VERTEBRATA
- Nomenclature