DIVERSITY IN LIVING ORGANISM

CBSE Class 9 Science Biology Diversity in living organisms question and answers

1.In what respects are lichens unusual plants?
Ans. lichen is a close partnership between an alga and a fungus. The algal cells grow in the fungal mycelium. Alga make food by photosynt hesis. The fungus provides shelter and protection to the alga. Thus, both the alga and the fungus benefit. This kind of association is called a symbiotic asso ciation.

2.Na me two coelenterates with diagrams. How do porifera n animals differ from coelenterate animals?
Ans.Examples of coelenterates. Poriferans are the simplest multicellular and branched. The cells are loosely held together and do not form tissue Coelenterates have one continuous central cavity called coelentron.



3.Differentiate between the heart of a fish and a bir ds?
Ans.Heart of fish is two chambered – auricle an d ventricle whereas birds have four chambered heart.

4.What is the difference notochord and nerve cord?
Ans.Notochord is a solid stiff but flexible rod like structure gives vertebral column in higher chordates (animals) while nervecord is a sol id or hollow tube like structure gives brain and spinal cord (nervous syst em)

5.Name the group of plants known a s “Amphibians of plant w orld ”. Mention th eir three important characters.
Ans.Bryophytes are the plants which lives on la nd and in water so they are called amphibians of the plant kingdom. These plants shows following character -
(a) The plant body is either thallus – like (thall oid) or leaf like (foliose)
(b) True leaves and roots are lacking; the plants are anchored to the soil by means of filamentous rhizoids.
(c) Plant body is green and autotrophic
(d) The vascular tissue are absent.

6.Give three points of how birds have adapted themsel ves to an aerial mode of life.
Ans.daptations of birds to aerial mode of lif e.
(a) Their body is covered with feathers.
(b) Forelimbs are modified into wings
(c) They have hollow bones which helps them in fli ght.

7.Give difference between vertebrates and invertebrat es.
Ans.





8.Define – sporophyte and gametophyte
Ans. sporophyte – It is the diploid (2n) phase or i ndividuals in the life of an organism and produce spores.
Gametophyte – It is the haploid (n) phase or indiv iduals in the life – cycle of an organism and produce gametes for sexual reproduction.

9..What is Binomial nomenclature? Who proposed it?
Ans. It is the naming system in which the name of t he organism has two words first word is the name of ‘genus’ and second word is the name of ‘species’ of the organism. It was proposed by Carl Von Linnaeus.

10Write two charateristics of animals
Ans. Characteristics of animals – a) Animals are multicelluar organisms with hetero trophic mode of nutrition.
b) They have power of locomotion and possess nerv ous system.


11.Write the main characteristics of Mammalia
Ans. Characteristics of mammalia are –
a) Mostly terrestrial but found in all types of h abitats
b) Body is of varied shape divisible into head, n eck, trunk and tail.
c) Skin covered with hair and has sweat glands
d) They possess mammary glands which produce milk
to nourish the young ones
e) Respiratory organs are lungs only.
f) The heart is four – chambered

12.What are gymnosperms .
Ans. Characteristics of gymnosperms.
a) The stem is erect aerial branched or unbranh ced.
b) The leaves are usually dimorphic i.e., prese nce of two types of leaves on a plant.
c) These are naked seeded plants i.e., their ovul es are not enclosed in the ovary.
d) The microsporophyll (male reproductive organ) and megasporphyll (female reproductive organ) are compactly arranged around t he central axis forming male cone & female cone respectively

13.What is classification? What is the need of classi fication? What is the basis of classification?
Ans. Classification – The process of grouping simi lar things into groups or categories on the basis of similarities and differences is called classification. Need of classification – It is very difficult to study large number of organisms individually. So organism having similar characters grouped together and the studied easily. Classification – Cell structure, mode & source fo r the nutrition and body organization.

15.Name the group of plants with the f o llowing char acters :
a) Plants with out root, stem, leaf and flowers.
b) Plants lacking chlorophyll.
Ans.

16.Name the various units of classification.
Ans.Units of classification are – species, Genu s family, order, class, Phylum (Division), Kingdom.

17. Why are bacteria and fungi classified along with pl ants?
Ans.acteria are kept under plants because they are mostly non-green and they possess cell wall. Fungi is kept under plants becau se it do not move but it lacks chlorophyll and derive nutrition from dead organic matter or by other methods.

18. Give difference between bony and cartila ginous fishes.
Ans.n bony fishes skeleton is bony (made up of bones) while in cartilaginous fishes skeleton is made up of cartilage.

19. Write characteristics of Aves.

Ans.haracteristics of aves are –
(i) Body is covered with feathers divided into hea d, neck and tail.
(ii) Birds are bipedal. The fore-limbs are modifie d into wings for flight.
(iii) Mouth is surrounded by a beak. Teeth are abs ent.
(iv) Skeleton is light because the long bones are hollow and contain air cavities.
(v) Respiration is by lungs which have air-sacs.
(vi) The heart is four – chambered.

20. You are given an assortment of plants on laboratory table. What characteristics will you look for in order to label a particular sp ecimen as –
(a) Angiosperm
(b) Moss
(c) Algae
(d) Fungi (e) Gym nosperm.
Ans.Angiosperm – Flowering plants
Moss - Leaves and roots are absent, presence of rhizoids.
Algae - Absence of stem, root and lea ves, presence of pigments.
Fungi - Non-green, made up of hyphae
Gymnosperm – Naked – seeded plants, i.e, seeds are not enclosed within the fruit.

21. What are the major divisions of the kingdom planate ? What is the basis of these divisions?
Ans.Major division of kingdom plantae – thallop hya, bryophyta, pteridophyta, gymnosperms and angiosperms. This kingdom includes Basis for classification –
(a) All organisms which are multicellular, eukaryo tic and green autotrophs.
(b) Green plants are further classified on the bas is of differentiation of the plant body.
(c) Second level of classification plant body has vascular tissue or not. Further classification is based on
(i) whether seeds are pr esent or not.
(ii) Whether seeds are enclosed within fruit or not.

22. Write characteristics of kingdom Animalia.
Ans.Characteristics of kingdom animalia are
(a) Animals are multicellular, eukaryotic organism s
(b) Animal nutrition is heterotrophic. They lack p hotosynthetic pigments.
(c) Animal lack cell walls.
(d) Animals possess the power of locomotion
(e) Most Animals have a nervous system which is us ed to coordinate their body actions and response.
(f) In sexual reproduction, animals produce haploi d male gametes (sperms) and female gametes.

23. Name two egg laying mammals.
Ans. Mammals give birth to young one but some mamma ls lay eggs like – platypus and echidna

24 Mention the features of vertebrates
Ans.a) Presence of tubular, dorsal, hollow nerve co rd.
b) Presence of a solid, rod – like stru cture called the notochord at some stage.
c) triploblastic and coelomate
d) Presence of post – anal tail (reduce d or absent in many adult chordates)

25 Give the technical name of the following –
(a) pea (b) potato (c) tiger (d) humans
Ans. a) P isum sativum
b) Solanum tuberosum
c) Panthera tigris
d) Homo sapiens

26 How pteridophytes different from phanerogams?
Ans. Pteridophyta has hidden reproductive organs. E xternal flower or seeds are absent. In phanerogams, well developed reproductive organs which produce seeds are present

27 What is the basis of grouping organisms into live kingdoms?
Ans. Basis for the classification of five kingdom c lassification –
a) Cell structure
b) Mode and source of nutrition
c) Body organization

28 Define – (a) bilateral symmetry (b) coelom (c) Triptoblastic
Ans.Bilateral symmetry – Body can be divided into tw o similar halves only by one plane that passes through the central or median axis eg – tortoise, humans.
Coelom – It is the body cavity which is lined externally as well as by regular layer of mesoderm
Triploblastic – When the body of an animal develops form three germ layer – ectoderm, mesoderm and endoderm, are called triplob lastic



29 Write characteristics of a n giosperms
Ans. Characteristics of angiosperms –
a) The angiosperms are the dominant group of land plants. These are the most common flowering plants.
b) The angiosperms are seed bearing plants and th e seeds are enclosed inside the fruit formed from ovary.
c) Carpel is like of megasporophyll as gymnosperms, but it is differentiated ovary, style and stigma
d) The pollen grain is received by the stigma causing pollination.
e) Ovary develops into fruit and ovule s into seeds after the act of fertilization.