NCERT Solutions for Class 9 Science Chapter 7

NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms Intext Questions Page 81, Page 82, Page 83, Page 85, Page 88, Page 94 and Exercises solutions in English Medium updated for new academic session 2020-21 download in PDF form free.

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NCERT Solutions for Class 9 Science Chapter 7

Class:	9
Subject:	Science – विज्ञान
Chapter 7:	Diversity in Living Organisms

9th Science Chapter 7 Answers in English & Hindi Medium

NCERT Solutions for Class 9 Science Chapter 7 Diversity in Living Organisms all Intext questions and chapter ending exercise question answers are given below updated for new academic session 2020-21. Solutions are available in Hindi Medium as well as English Medium format. NCERT Solutions and Offline apps are based on latest NCERT Books 2020-21.

How do gymnosperm and angiosperms differ from each other?

Gymnosperm have naked seeds whereas Angiosperms have seed inside their fruits.

What are phanerogams? Name its two groups along with criteria of division.

(i) Phanerogams are higher plants that bear flower and seeds.
(ii) Seeds are the result of reproductive process.
(iii) They contain an embryo which store food.
(iv) They are further divided into Gymnosperms and Angiosperms.
(v) Angiosperm have seeds inside the fruits.

What is the primary characteristics on which the first division of organism is made?

Whether the organism is prokaryotic or eukaryotic is the primary characteristic.

Why is there a need to classify living organisms?

(i) It enables us to study living things more easily and understand them better.
(ii) It helps to identify and communicate about the large number of living organisms on earth.
(iii) It helps to trace the possible origins of different living organisms to determine any relationship.

State the characteristic feature of thallophytes? Name two thallophytes which are predominantly aquatic?

Thallophytes body is not well differentiated, no vascular tissue present, usually contain green pigment and have cell wall made up of cellulose. Spirogyra, Ulva are thallophytes and are aquatic.

List any three differences between Aves and Mammalia group.

Aves:
(a)They lay eggs.
(b) Do not have mammary glands.
(c) Their body is covered with feathers.
Mammalia:
(a) They give birth to young ones.
(b) They have mammary glands.
(c) Their body is covered with hairs.

Who proposed the system of binomial nomenclature for the organisms?

Carolus Linnaeus proposed the system of binomial nomenclature.

Write three characteristics each of the following groups of animals: (a) Platyhelmintes (b) Nematoda.

(a) Platyhelmintes:
(i) Their body is bilaterally symmetrical.
(ii) They are triploblastic
(iii) There is no coelom.
(b) Nematoda:
(i) Their body is cylindrical and bilaterally symmetrical.
(ii) Pseudocoelom is present.
(iii) They are triploblastic.

Questions for Practice on 9th Science Chapter 7

Question 1:
Differentiate between Monera and Fungi on the following grounds:
(a) Body organisation
(b) Prokaryotic/Eukaryotic
(c) Cell wall
(d) Mode of nutrition
Name an organisms belongings to each of these kingdom.
Answer 1:
Monera:
(a) Unicellular undefined nucleus.
(b) Prokaryotic
(c) Some have cell wall made up of cellulose.
(d) Autotrophic nutrition
Example: Blue green algae, bacteria.
Fungi :
(a) Multicellular at later stage organised body.
(b) Eukaryotic
(c) All have cell wall made up of chitin.
(d) Heterotrophic nutrition.
Example: Yeast, Mashroom

Question 2:
Define the given terms and give one example of each:
(a) Bilateral symmetry
(b) Coelom
(c) Triploblastic
Answer 2:
(a) Bilateral symmetry: The organisms which can be divided into two identical equal halves, i.e., like mirror images are said to possess bilateral symmetry.
(b) Coelom: It is the body cavity of the organisms. It is necessary for proper functioning of the body, e.g. heart has coelom which helps it to contract and expand.
(c) Triploblastic: These are the organisms derived from three embryonic germ layers.

Important Questions on 9th Science Chapter 7

What are the advantages of classifying organisms?

There are millions of species on this earth. For anybody, it is impossible to study about each of them in his lifetime. Classification makes it easy to study the organisms; on the basis of certain common characters.

अपने चारों ओर फैले जीव रूपों की विभिन्नता के तीन उदाहरण दें।

जीवों में तीन प्रकार विभिन्ता प्रायः देखी जाती हैं:
आकार: कुछ जीव जैसे बैक्टीरिया अतिसूक्ष्म होते है तो दूसरी ओर ह्वेल जैसे जीव कई मीटर तक लम्बे होते हैं।
जीवन काल: कुछ जीवों जैसे मच्छर का जीवन काल अति न्यून होता है जबकि कुछ पौधे सैकड़ों साल जिन्दा रहते है।
रंग: कुछ जीव रंगहीन (पारदर्शी तक) होते है तो कुछ विभिन्न आकर्षक रंगों युक्त होते हैं।

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

We need to look at the fact if given character is present in a small number of organisms or a larger number of organisms. In the first case, the commonality of characters would represent a species. In the latter case, the commonality of characters would represent a higher taxa; like genus, family, order or phylum.

Explain the basis for grouping organisms into five kingdoms.

Following points explain the basis of grouping organisms into five kingdoms. Organization of nucleus: Organisms with unorganized nucleus are kept under the kingdom Monera. Those with organized nucleus are kept in other kingdoms.
Number of cells: Unicellular eukaryotes are kept in the kingdom Protista, while multicellular eukaryotes are kept in other kingdoms.
Mode of nutrition and presence of cell wall: Hetereotrophic organisms in which cell wall is present are taken under the kingdom fungi.
Autotrophic organisms in which cell wall is present are taken in the kingdom Plantae. Organisms in which cell wall is absent are taken in the kingdom Animalia.

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

The major divisions of Plantae and the basis for these divisions are as follows:
Thallophyta: Simple body design; with no differentiation into root, stem and leaves.
Bryophyta: Body is differentiated into stem and leaf-like structures. Vascular system is absent.
Pteridophyta: Body is differentiated into root, stem and leaves. Vascular system is present.
Reproductive organs are inconspicuous. Seeds are not produced.
Gymnosperms: Seeds are naked.
Angiosperms: Seeds are covered.

जीवों के प्रारंभिक विभाजन के लिए किस मूल लक्षण को आधार बनाया गया?

जीवों के प्रारंभिक विभाजन के लिए उनके निवास स्थान को वर्गीकरण का आधार बनाया गया।

किस आधार पर जंतुओं और वनस्पतिओं को एक – दूसरे से भिन्न वर्ग में रखा जाता है?

निम्नलिखित आधारों पर जंतुओं और वनस्पतिओं को एक – दूसरे से भिन्न वर्ग में रखा जाता है:
कोशिकीय संगठन के आधार पर
कोशिका भित्ति के आधार पर
पोषण क्रिया के आधार पर

आदिम जीव किन्हें कहते हैं? ये तथाकथित उन्नत जीवों से किस प्रकार भिन्न हैं?

वो जीव समूह, जिनकी शारीरिक संरचना में प्राचीन काल से लेकर आज तक कोई खास परिवर्तन नहीं हुआ है, आदिम जीव अथवा निम्न जीव कहलाते हैं। ये जीव समूह, उच्च जीवों से कोशकीय संगठन तथा कार्यों में भिन्न होते हैं। उच्च जीवों का संगठन प्रायः जटिल होता है।

क्या उन्नत जीव और जटिल जीव एक होते हैं?

नहीं, क्योंकि विकास के दौरान जीवों में जटिलता की संभावना बनी रहती है। इसलिए पुराने जीवों को साधारण और नए जीवों को अपेक्षकृत जटिल कह सकते हैं।

मोनेरा अथवा प्रोटिस्टा जैसे जीवों के वर्गीकरण के मापदंड क्या हैं?

मोनेरा अथवा प्रोटिस्टा एक कोशिकीय जीव हैं। अतः इनके वर्गीकरण के लिए निम्नलिखित मापदंड होंगे:
कोशिकीय संगठन
कोशिका भित्ति
केन्द्रक की उपस्थिति या अनुपस्थिति
पोषण के प्रकार

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

In the plant kingdom, morphological characters are taken into consideration while deciding about the divisions. Morphology is the study of shapes and forms of various parts. In the animal kingdom, anatomical characters are taken into consideration while deciding about subgroups. Anatomy is the study of various organs’ design in animals.

वर्गीकरण के विभिन्न पदानुक्रमों में किस समूह में सर्वाधिक समान लक्षण वाले सबसे कम जीवों को और किस समूह में सबसे ज्यादा संख्या में जीवों को रखा जाएगा?

सर्वाधिक समान लक्षणों वालें सबसे कम संख्या वाले वर्ग को जाति (स्पसीज) कहते है क्योंकि वर्गीकरण में यह निम्नतम स्तर पर है। जबकि सर्वाधिक संख्या वालें समूह की जगत कहते है क्योंकि वर्गीकरण में यह उच्चतम स्तर पर है।

सरलतम पौधों को किस वर्ग में रखा गया है?

सरलतम पौधों को थैलोफाइटा (Algae) वर्ग में रखा गया है।