7 diversity in living organisms concepts - · pdf filediversity in living organisms concepts...

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© GOYAL BROTHERS PRAKASHAN

DIVERSITY IN LIVING ORGANISMS

CONCEPTS1. There are more than a million kinds of living things exhibiting an infinite variety in form,

structure and living places.2. Classification puts things in order.3. The use of important distinguishing features forms the basis of classification.4. The process of grouping similar things into groups and categories on the basis of similarities

and dissimilarities is called classification.5. The system of classification was devised by Carolus Linnaeus.6. The naming of organisms is called nomenclature.7. The science of classification is called taxonomy.8. Carolus Linnaeus is called the father of taxonomy.9. Species is a group of organisms capable of interbreeding to produce fertile offspring.

10. Genus is a group of similar and closely related species.11. Binomial name has two parts — genus and species.12. The names given to living organisms following the binomial system are called scientific

names.13. The genus name begins with a capital letter, the species name begins with a small letter.14. R.H. Whittaker was the first one to propose a five-kingdom classification in 1969.15. Monera, Protista, Fungi, Plantae and Animalia are included in five–kingdom

classification.16. Kingdom Plantae is divided into two subkingdoms — Cryptogamae and Phanerogamae.17. The simplest plants belong to the division Thallophyta.18. Lichen is a symbiotic association of algae and fungi.19. Plants belonging to bryophyta are called amphibians of the plant kingdom.20. Bacteria are often called “fission plants” as they multiply by binary fission.21. Biologists have identified, named, classified and described more than a million types of

animals inhabiting the earth.22. Animals differ in their structure ranging from single celled to multicellular animal.23. All animals are eukaryotic organisms.24. Most animals have a high level of tissue differentiation.25. Animal nutrition is heterotrophic.26. Animal cells lack cell wall.27. Animals possess the power of locomotion.28. Two main criteria, used to classify animals are —

(i) presence or absence of vertebral column. (ii) cellular organisation.29. The first group of animals is invertebrates — animals without backbone.30. The second group of animals is vertebrates — animals having backbone or vertebral

column.

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Question Bank in Science Class-IX (Term-II)

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31. Based on the cellular organisation, animals can be divided into — protozoa and metazoa.32. Protozoa represent the one-celled animals/unicellular animals, e.g., Amoeba, Paramecium,

Euglena, Trypanosoma.33. Metazoa represents the many-celled animals/multicellular animals, e.g., Hydra, earthworm,

corals, flatworms, insects, frogs, etc.34. The phyla, in order of their increasing complexity beginning from the simple single-celled

forms to complex form are like these — protozoa, porifera, cnidaria, platyhelminthes,nematoda, annelida, arthropoda, mollusca, echinodermata, hemichordata and chordata.

35. Symmetrical body shape means the parts of an animal body are arranged in such a way thatit can be cut into two similar halves by one or more planes.

36. Germ layers are the primary layers of cells which differentiate in the animal embryo.37. Phylum protozoa includes minute, microscopic, eukaryotic organisms, e.g., Amoeba,

Euglena, Trypanosoma.38. Phylum porifera includes mostly sessile or stationary sea animals, having porous body e.g.

Sycon, Leucosolenia, etc.39. Phylum coelenterata includes radially symmetrical, multicellular, aquatic animals, e.g.,

Hydra, Obelia, etc.40. Phylum platyhelminthes includes bilaterally symmetrical, triploblastic, mostly parasitic

animals. e.g., liver fluke, blood fluke, tapeworm.41. Phylum nematoda includes mostly parasitic animals having narrow, elongated, cylindrical

unsegmented body. e.g. roundworm, pinworm, filarial worm, etc.42. Phylum annelida includes free living coelomic animals having metameric segmentation, e.g.,

earthworm, sea-mouse, etc.43. Phylum arthropoda are the largest group of animals and its main feature is jointed legs and

body is divided into three regions— head, thorax and abdomen. e.g., prawn, crab, housefly,mosquito, etc.

44. Phylum mollusca includes mainly aquatic animals having soft, unsegmented body. e.g., snail,mussel, cuttlefish.

45. Phylum echinodermata includes star-shaped, spherical or elongated exclusively marineanimals, e.g., starfish, brittle star, sea cucumber, etc.

46. Phylum hemichordata posses characters of both vertebrates and invertebrates, e.g., tongueworm, Rhabdopleura.

47. Phylum chordata – the animals with vertebral column like horse, man etc.

I. SUMMATIVE ASSESSMENT

NCERT QUESTIONS WITH THEIR ANSWERS

SECTION A : IN-TEXT QUESTIONSPage 80Q.1. Why do we classify organisms?Ans. There are more than a million kinds of living things exhibiting an infinite variety in form,

structure and living places. It is not possible to know everything about all the organisms. We

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can study just a few representatives and get the idea about that group. Classification makesthe study of such a wide variety of organisms easy. It is also important to understand theinterrelationship among different groups of organisms. Classification serves as a basis for thedevelopment of other biological sciences as well.

Q.2. Give three examples of the range of variations that you see in life-forms around you.Ans. The range of variation in life forms is vast. Most common of these are size (living form ranges

from microscopic bacteria to giant blue whale), colour (living beings range from colourless oreven transparent worms to brightly coloured birds and flowers), and lifespan (like insectswhich live for only few days while pine trees live for thousand of years).

Page 82Q.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?

Ans. (b) The kind of cells they are made should be the basic characteristic for classifying organ-isms. Classification should be based on fundamental characteristic and cell is the funda-mental unit of all living forms.An eukaryotic cell has membrane-bound organelles, including a nucleus, which allowcellular processes to be carried out efficiently in isolation from each other. Therefore,organisms which do not have a clearly demarcated nucleus and other organelles wouldneed to have their biochemical pathways organised in very different ways. This wouldhave an effect on every aspect of cell design. Further, nucleated cells would have thecapacity to participate in making a multicellular organism because they can take upspecialised function. Therefore, this is a basic characteristic of classification.

Q.2. What is the primary characteristic on which the first division of organisms is made?Ans. The primary characteristics on which the first division of organisms is made, is whether the

cells occur singly or they are grouped together. Cells that group together to form a singleorganism use the principle of division of labour. In such a body design, all cells would notbe identical. Instead, groups of cells will carry out specialised functions. This makes a verybasic distinction in the body designs of organisms.

Q.3. On what bases are plants and animals put into different categories?Ans. Plants and animals are put into different categories on the basis of whether they can produce

their own food or not. Being able to produce one’s own food versus having to get food fromoutside would make very different body designs necessary. In this way, plants and animalshave been categorised into different groups.

Page 83Q.1. Which organisms are called primitive and how are they different from so called advanced

organisms?Ans. Organisms which possess simple body organisation are called primitive organism.

They differ from so called advanced organisms as all the activities of life are performed bya single cell. i.e. they do not possess different organs or organ systems for performing variousfunctions as found in advanced organisms.

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Q.2. Will advanced organisms be the same as complex organisms? Why?Ans. Yes. As there is a possibility that complexity in design of an organism will increase over

evolutionary time, it can be said that the younger organisms or advanced organisms are morecomplex in comparison to older one.

Page 85

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

Ans. The organisms belonging to kingdom Monera are classified on the basis of following criteria :These organisms do not have a defined nucleus or organelles, nor do any of them showmulticellular body designs.Some of them have cell wall, some not.Mode of nutrition may be autotrophic or heterotrophic.

The organisms belonging to kingdom Protista are classified on the basis of following criteria:The organisms are unicellular, eukaryotic organisms i.e. well defined nucleus and othercell organelles are present.Some of these organisms have hair like cilia or whip-like flagella for movement.Mode of nutrition may be autotrophic or heterotrophic.

Q.2. In which kingdom will you place an organism which is single celled, eukaryotic and photo-synthetic?

Ans. The organism, which is single celled, eukaryotic and photosynthetic belongs to the kingdomprotista.

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

Ans. In the hierarchy of classification, the category “species” has the smallest number of organismswith a maximum of characteristics in common.On the other side, the category “kingdom” has the largest number of organisms as it is at thetop level of the hierarchy.

Page 88

Q.1. Which division among plants has the simplest organisms?Ans. The plants belonging to the division thallophyta do not have well-differentiated body

organisation.Q.2. How are pteridophytes different from phanerogams?Ans. Pteridophytes and phanerogams differ mainly in their reproductive organs.

The reproductive organs of pteridophytes are not very well developed, and they are thereforecalled cryptogams or those with hidden reproductive organs.On the other hand, plants with well differentiated reproductive organs that ultimately makeseeds are called phanerogams.

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

Ans. Gymnosperms Angiosperms

(a) Naked seeded plants- seeds are not (a) Seed bearing plants, i.e. seeds areenclosed within the fruit. enclosed inside the fruit formed.

(b) Occupy an intermediate position between (b) Dominant group of land plants andthe pteridophytes and the angiosperms. most common flowering plants.

Page 94

Q.1. How do poriferan animals differ from coelenterate animals?Ans. Poriferan animals differ from coelenterate animals in the following ways :

Poriferan animals Coelenterate animals

(a) Poriferans are ‘pore-bearing’ animals, (a) Coelenterata means hollow gut - thei.e., the body has many pores all over. body cavity with a single opening to

the outside coelenteron.

(b) They have cellular level of body (b) They have tissue level of bodyorganisation. organisation with a distinct division

of labour.

(c) Characteristic canal system is present. (c) Gastrovascular cavity or coelenteronis the main feature.

Q.2. How do annelids differ from arthropods?Ans. Annelids differ from arthropods in the following ways :

Annelids Arthropods

(a) The body is composed of rings or (a) Metameric segmentation is absent.segment-showing metameric segmentation.

(b) Body is soft, no hard skeleton. (b) Body is covered with hardexoskeleton made up of chitin.

(c) True body cavity is present. (c) Body cavity is filled with blood,known as haemocoel.

(d) Blood vascular system is of closed type. (d) Blood vascular system is of open-type.

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Q.3. What are the differences between amphibians and reptiles?Ans. The differences between amphibians and reptiles are as follows :

Amphibians Reptiles

(a) Amphibious in nature, i.e. found in (a) Truly terrestrial animals.water and on land both.

(b) Skin is smooth or rough but without scale. (b) Skin is with scales.(c) Head and trunk distinct. (c) Body is distinctly divisible into

head, neck and trunk.(d) Heart is three chambered. (d) Heart is incompletely four-chambered.

Q.4. What are the differences between animals belonging to the aves group and those in themammalia group?

Ans. Differences between animals belonging to the aves group and those in the mammalia groupare as follows :

Aves Mammalia

(a) Feathered animals-body is covered (a) Skin is covered with hair.with feathery exoskeleton.

(b) The body is divisible into head, neck, (b) The body is divided into headtrunk and tail. thorax and abdomen.

(c) Endoskeleton is light, bones have air (c) Exoskeleton is strong, bones have nocavities. air cavities.

(d) Respiration occurs through large sacs. (d) Respiration occurs through minuteair-sacs.

(e) They are oviparous i.e., egg laying. (e) They are viviparous i.e., give birth toyoung ones.

SECTION B : QUESTIONS AT THE END OF CHAPTER

Q.1. How would you choose between two characteristics to be used for developing a hierarchy inclassification?

Ans. The characteristics to be used for developing a hierarchy in classification may be the cellstructure, mode and source of nutrition and body organisation of the organisms.

Q.2. Explain the basis for grouping organisms into five kingdoms.Ans. The basis for grouping organisms into five kingdoms are their cell structure, mode and source

of nutrition and body organisation.Q.3. What are the major divisions in the plantae? What is the basis for these division?Ans. Major divisions in the plantae and the basis on which they have been classified can be shown

by the following flow chart :

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Q.4. What are the advantages of classifying organisms?Ans. Classification is the basic method which humans employ to organise the living world. It has

the following advantages :1. Classification makes the study of the wide variety of organisms existing in the living

world convenient, easy and time-saving.2. Classification projects before us a picture of all life forms at a glance.3. Classification tells us about the interrelationships between different groups of organisms,

and in turn provides us information about their evolution.4. It allows easy means of communication of information to other people.5. Classification is an information storage system and the biologists need it for the specific

organism they work with.6. Classification serves as a base for all other disciplines of biology.7. Various fields of applied biology such as agriculture, environmental biology and public

health depend on the correct identification and classification of disease-causing organismsand insect pests.

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

Ans. The characteristics of body organisation used for classification of plants will be very differentfrom those important for classifying animals. In case of plants (i.e. make their own food),division is made further according to the level of organisation.In case of animals, subgroups are formed on the basis of how the body of the individualdevelops, and organises in different parts, what are the specialised organs found for differentparts, what are the specialised organs found for different functions, etc.

Q.6. Explain how animals in vertebrata are classified into further subgroups.Ans. Vertebrata is classified into five subgroups. These are

1. Pisces 2. Amphibia 3. Reptilia 4. Aves 5. MammaliaClass PiscesThis class includes all fishes.Characters1. These are exclusively adapted to aquatic life.2. The body is covered with scales.3. Body is streamlined.4. Fins are present but limbs are absent.5. Respiration takes place through gills.

Class Amphibia (Gr. amphi = both, bios = life, the vertebrates leading twolives / dual life)The amphibians are the first land vertebrates, but they are partly terrestrial and partly aquatic.Characters1. Head and trunk distinct; neck and tail may or may not be present.2. Limbs tetrapodus (four-limbed), pentadactyl type (five-fingered).

Class Reptilia (L. rapture = to creep; creeping vertebrates)These are first truly terrestrial animals living in warmer regions.Characters1. Cold-blooded animals.2. Body is divisible into head, neck and trunk. Tail is well developed in some, while it is

reduced in others.Class Aves (L. aves = bird)The birds are described as ‘feathered reptiles’ that have developed the power of flight.Characters1. Warm blooded animals. Body is covered with a feathery exoskeleton.2. The body is divisible into head, neck, trunk and tail.

Class Mammalia (L. mamma = breast; the mammals)Mammals are the most evolved group of organisms and are found in diverse habitats rangingfrom deserts, polar ice caps, oceans, mountains, forests and grasslands.

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They are named mammals as all of them possess mammary glands (milk-producing glands).Mammals are the only animals which feed their young ones with milk.Characters1. Warm-blooded animals.2. Skin is covered with hair. Hairs are provided with sweat glands.3. The body cavity is unequally divided into two parts by a muscular partition called

diaphragm.

ADDITIONAL QUESTIONS(As Per CCE Pattern)

A. Very Short Answer Questions (1 Mark)

Previous Years' QuestionsQ.1. (a) A flowering plant whose embryo possesses single cotyledon (Give scientific term).

(b) A unicellular, eukaryotic aquatic organism (Name the kingdom) [2011 (T-II)]Ans. (a) Monocotyledonous plants (seeds with one cotyledon)

(b) kingdom Protista

Other Important QuestionsQ.1. Meena and Hari observed an animal in their garden. Hari called it an insect while Meena said

it was an earthworm. Name the character which confirms that it is an insect.Ans. Insect has three or more pairs of jointed legs.Q.2. Name the scientist who proposed five kingdom classification.Ans. Robert H. WhittakerQ.3. What is the mode of nutrition in fungi?Ans. SaprophyticQ.4. What are the divisions of living organisms?Ans. Living organisms are mainly classified into two divisions

(i) Animalia (ii) PlantaeQ.5. What is the basis of classification of plants?Ans. Plants are divided on the basis of seed bearing or non-seed bearing character.Q.6. What is Systema Naturae?Ans. Systema Naturae is a book written by Linnaeus which includes a number of species of animals

and plants.Q.7. What is the scientific name of human?Ans. Homo sapiens sapiensQ.8. What is cryptogamae?Ans. Cryptogamae is a division of plantae which includes plants that are nonflowering and non-seed

bearing.Q.9. What are the divisions of cryptogamae?Ans. Divisions of Cryptogamae are :

(i) Thallophyta (ii) Bryophyta, and (iii) Pteridophyta

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Q.10. What are the examples of thallophyta?Ans. Examples of thallophyta are algae and fungi.

Q.11. What are the parts of scientific name?Ans. Scientific name has two parts. One is generic name and another is specific name.

Q.12. Write the scientific names of pea and peacock?Ans. Pea - Pisum sativum

Peacock - Pavo cristatusQ.13. What are amphibians of the plant kingdom?Ans. Bryophytes are the amphibians of plant kingdom.

Q.14. What is the basis of classification of animals?Ans. The basis of classification of animals is single cell, i.e., unicellular or protozoa and many cell,

i.e; multicellular or metazoa.Q.15. What are invertebrates?Ans. Invertebrates are animals without backbone.

Q.16. Which animal shows bilateral symmetry?Ans. Flat worms shows bilateral symmetry.

Q.17. What type of body symmetry is shown by Hydra?Ans. Body of Hydra is radially symmetrical.

Q.18. What is pseudocoel?Ans. Roundworms have pseudocoel. Pseudocoel is a cavity between the gut and the outer body

wall. In pseudocoel body cavity is not lined by peritoneum.Q.19. In which phyla, true body cavities are present?Ans. Annelida

B. Short Answer Questions - I (2 Marks)

Previous Years' QuestionsQ.1. Which organisms are called primitive? How are they different from the advanced organisms?

[2011 (T-II)]Ans. Organisms which possess simple body organisation are called primitive organism.

They differ from so called advanced organisms as all the activities of life are performed bya single cell i.e. they do not possess different organs or organ systems for performing variousfunctions as found in advanced organisms.

Q.2. What are the four main characteristics of chordates? [2011 (T-II)]Ans. Four main characteristics of chordates are

1. Presence of a tubular, dorsal, hollow nerve cord.2. Presence of a solid, rod-like structure called the notochord at some stage of life.3. Triploblastic and coelomate.4. Presence of a post anal tail (tail behind the anal opening); the tail is reduced or absent

in many adult chordates.Q.3. (a) Give one characteristic difference between primitive and advanced organisms.

(b) Name the phylum to which the following are included. [2011 (T-II)](i) Spider (ii) Cockroach (iii) Prawn (iv) Housefly

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Ans. (a) The activities of life are performed by a single cell in primitive organisms while there aredifferent organs for performing various functions in advanced organisms.

(b) (i) Spider – Arachnida (ii) Cockroach – Dictyoptera(iii) Prawn – Arthropoda (iv) Housefly – Arthropoda

Q.4. (i) Write one main characteristic feature that differentiates gymnosperms from angiosperms.(ii) Give one example of each of a gymnosperm and an angiosperm. [2011 (T-II)]

Ans. Gymnosperms Angiosperms

(i) Naked seeded plants – seeds are not (i) Seed bearing plants, i.e. seeds areenclosed within the fruit. enclosed inside the fruit formed.

(ii) Example of Gymnosperm is Cycas. (ii) Example of angiosperm is mustard.

Q.5. (i) Identify the class of animals having the following characteristic features.(a) The warm blooded animals that lay eggs and have four chambered heart and a covering

of feathers.(b) The cold blooded animals having scales and they breathe through lungs.(ii) Give one example of an animal belonging to each of these classes. [2011 (T-II)]

Ans. (i) (a) Aves (b) Reptilia(ii) (b) Aves Example – Duck

Reptilia Example – LizardQ.6. In the hierarchy of classification, which grouping will have the smallest number of organisms

with maximum characteristics in common and which will have the largest number oforganisms? [2011 (T-II)]

Ans. In the hierarchy of classification, the category ‘‘species’’ has the smallest number of organismswith a maximum of characteristics in common. On the other side, the category ‘‘kingdom’’has the largest number of organisms as it is at the top level of the hierarchy.

Q.7 Characteristics of some organisms are given. Identify their group and give one example ofeach. [2011 (T-II)](a) Single celled, eukaryotic and photosynthetic(b) The body is divided into segments, may be unisexual or hermaphrodite.

Ans. (a) Group – Protista Example – Algae(b) Group – Annelida Example – Earthworm

Q.8. (a) List two features which differentiate chordates from non-chordates.(b) In which phylum will you place the organisms which have

(i) calcareous spines on their body?(ii) the presence of holes or pores all over the body? [2011 (T-II)]

Ans. (a) Chordates Non-chordates

1. They have backbone. 1. They do not have backbone.2. Notochord present at some stage 2. Notochord is absent.

of development.

(b) (i) Phylum – Echinodermata (ii) Phylum – Porifera

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Q.9. How do the saprophytes get their food? Give two examples of a saprophyte. [2011 (T-II)]Ans. Saprophytes get their food from the dead remains of plants and animals.

Examples of Saprophytes are Mucor, RhizopusQ.10. List the major divisions in kingdom plantae. Write the characteristic features of any one of

them. [2011 (T-II)]Ans. For Flow-chart See Q.3 Page-75

Characteristic features of gymnosperms is that seeds are naked.Q.11. Explain Binomial Nomenclature? Name the scientist who has given it. Write its advantage ?

[2011 (T-II)]Ans. Binomial Nomenclature – It is the scientific nomenclature to name the living organisms.

Linnaeus introduced Binomial Nomenclature.Advantage – In this system it was a simple scheme for arranging plants so as to be able toidentify them again.

Q.12. List the conventions used for writing a scientific name. What is the importance of scientificnames? [2011 (T-II)]

Ans. It is a convention that genus name (generic name) is always written first with its initial letterin capital. Species name (specific name) is written after the genus name and its initial letteris always small. Both names of an individual are printed in italics. When handwritten both areunderlined, e.g., Rana tigrina (frog).Importance – The scientific names are unique, understood and followed all over the world.They are not changed easily.

Q.13. (a) How many chambers do the heart of fish, amphibians and mammals have?(b) Name the classes of vertebrates which lay eggs with shells. [2011 (T-II)]

Ans. (a) Fish have two – chambered heart, Amphibians have three chambered and mammals havefour – chambered heart.

(b) (i) Reptilia (ii) AvesQ.14. Why bryophytes are called the amphibians of the plant kingdom? [2011 (T-II)]Ans. Bryophytes are called the amphibians of the plant kingdom because they are the first plants

to live on land and in water.Q.15. Some reptiles live in water and yet lay eggs with tough covering unlike the amphibians. Why?

[2011 (T-II)]Ans. Because they are partly terrestrial and partly aquatic.

Q.16. How are fungi (i) similar and (ii) dissimilar to plants? [2011 (T-II)]Ans. (i) Fungi are similar to plants because both have a cellulose cell wall.

(ii) Fungi are disimilar to plants because plants are autotrophs and use chlorophyll (presentin chloroplasts) for photosynthesis. Whereas fungi are simply non-green plants which arenot photosynthetic.

Q.17. How do thallophytes and pteridophytes differ from each other? Write two differences.[2011 (T-II)]

Ans. Thallophytes Pteridophytes

1. No embryo is formed after fertilization. 1. Embryo is formed after fertilization.2. Vascular tissues. (xylem and phloem are absent. 2. Vascular tissues are present.

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Q.18. (a) List any three important features of vertebrates.(b) Name one reptile. [2011 (T-II)]

Ans. (a) Three important features of vertebrates are.1. Presence of a tubular, dorsal, hollow nerve cord.2. Presence of a solid, rod like structure called the notochord at some stage of life.3. Triploblastic and coelomate.

(b) LizardQ.19. Write two peculiar characters of sponges? [2011 (T-II)]Ans. Characters of Sponges

1. They live mostly in the sea (marine) but a few occur in freshwater.2. They are sessile or stationary with plant-like appearance.

Q.20. Why are bats not placed in birds (Two Points)? [2011 (T-II)]Ans. 1. Bats are not placed in birds because bats possess mammary glands (milk producing

glands).2. Secondly cutaneous glands are absent in birds but present in bats.

Q.21. (a) What are saprophytes? [2011 (T-II)](b) Name the kingdom to which they belong.(c) What is the cell wall of fungi made up of ?

Ans. (a) Saprophytes are the organisms which feeds on dead organism and organic matter.(b) Saprophytes belong to the kingdom Fungi(c) Cell wall of fungi is made up of chitin and cellulose.

Q.22. (a) Identify the class of following organism having following features :(i) Slimy skin and three chambered heart.

(ii) Covering of feather and four chambered heart.(b) List two important characteristics of phylum Nematoda. [2011 (T-II)]

Ans. (a) (i) Class – Amphibia (ii) Class – Aves(b) Two important characteristics of phylum Nematoda are

1. They are either parasitic (in plants and animals) or free-living (aquatic-freshwater orsea water, or terrestrial), most are free-living

2. They have narrow, elongated and cylindrical bodies.Q.23. What is notochord? Mention its function. [2011 (T-II)]Ans. Notochord is a long rod-like structure that separates the nervous tissue from the gut and runs

along the back of the animal.Q.24. Write the main features of Fungus plants. [2011 (T-II)]Ans. Main features of Fungus plants are –

Fungi are non-green (lacking chlorophyll) eukaryotic organisms. Fungi are made up of slendertubes called hyphae (singular hypha). The mass of hyphae which form an individual is calledthe mycelium (plural mycelia). Fungi are heterotrophic in nutrition, and the food is obtainedeither saprophytically (from dead organic matter) or parasitically (from living tissues ofother organisms). Most fungi are saprophytes.Cell wall consists of a tough complex sugar called chitin.Reserve food material consists of glycogen.Some fungi live in symbiotic relationship with blue-green algae, as in lichens.

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Examples : Yeast, Rhizopus, mushrooms, moulds (Aspergillus, Penicillium).Fungi, in the traditional system of classification, were kept under plants because of thepresence of cell wall.

Q.25. Enlist four main features of organisms placed in protista. [2011 (T-II)]Ans. 1. This kingdom includes unicellular algae, diatoms and protozoans.

2. The organisms in this kingdom are unicellular, eukaryotic organisms (as well-definednucleus and other cell organelles are present).

3. Mode of nutrition is either autotrophic (as in algae and diatoms) or heterotrophic (as inprotozoans).

4. Some protists bear hair-like cilia or whip like flagella for movement. In some protists likeAmoeba movement takes place by pseudopodia (false feet).

Q.26. Give four main features of phylum coelenterata. [2011 (T-II)]Ans. 1. All coelenterates are found in water. Most

of the forms live in the sea (marineforms), except a few, like Hydra, whichare found in freshwater.

2. Body is radially symmetrical.3. These are the first of multicellular

animals which possess tissue levelorganisation with a distinct division oflabour.

4. The body has a single, sac-like centralcavity, called coelenteron or thegastrovascular cavity, with only oneopening.

Q.27. (a) What are the two adaptive features of birds? [2011 (T-II)](b) What is the scientific name of ostrich?

Ans. (a) Two adaptative features of birds are1. Warm blooded animals. Body is covered with a feathery exoskeleton.2. The body is divisible into head, neck, trunk and tail.

(b) Scientific name of ostrich is struthio.Q.28. Why is there a need for classification and systematic naming of living organisms?

[2011 (T-II)]Ans. There are more than a million kinds of living things exhibiting an infinite variety in form,

structure and living places. It is not possible to know everything about all the organisms. Wecan study just a few representatives and get the idea about that group. Classification makesthe study of such a wide variety of organisms easy. It is also important to understand theinterrelationship among different groups of organisms. Classification serves as a basis for thedevelopment of other biological sciences as well.

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Q.29. How do reptiles differ from amphibians? [2011 (T-II)]

Ans. Amphibians Reptiles

(a) Amphibious in nature i.e. found (a) Truly terrestrial animals.in water and on land both.

(b) Skin is smooth or rough but (b) Skin is with scales.without scale.

(c) Head and trunk distinct. (c) Body is distinctly divisible into head,neck and trunk.

(d) Heart is three chambered. (d) Heart is incompletely four-chambered.

Q.30. (a) Define cryptogams? [2011 (T-II)](b) Name the division of plant kingdom having amphibian plants.

Ans. (a) Cryptogams are those plants which do not produce external flowers or seeds. Thus, theyare considered to bear hidden reproductive organs. The cryptogams are, therefore, alsoknown as flowerless plants, seedless plants or lower plants.

(b) Bryophyta is the division of plant kingdom having amphibian plants.Q.31. Bats can fly still they are placed in mammal. Why? [2011 (T-II)]Ans. Bats are placed in mammals because they possess mammary glands (milk producing glands).

Mammals are the only animals which feed their young ones with milk.Q.32. Give reasons for each of the following. [2011 (T-II)]

(a) “Blue-green algae is placed in Monera and not in plantae”(b) “Bryophytes and Pteridophytes grow in moist and shady places”.

Ans. (a) Blue green algae is placed in Monera because it is a prokaryotic, i.e., they do not havea defined nucleus and lack cell organelles.

(b) Bryphytes and Pteridophytes need moist and shady places because their life cycle can notcomplete without water or moist.

Q.33. (a) Write any two important features that are present in all chordates. [2011 (T-II)](b) Mention one difference between triploblastic and diploblastic animals.

Ans. (a) 1. Presence of a tubular, dorsal, hollow nerve cord.2. Triploblastic and coelomate

(b) An animal with a body wall composed only of two layers, ectoderm and endoderm arediplablastic. An animal having a body composed of three embryonic cell layers – theectoderm, mesoderm and endoderm are triploblastic.

Q.34. Give two differences between bony fish and cartilaginous fish. Give one example of each.[2011 (T-II)]

Ans. Bony Fish Cartilaginous Fish

1. Skeleton is made of bones. 1. Skeleton is made entirely of cartilage.2. Bony fish have a swim bladder 2. They do not have swim bladder and therefore

which acts as a hydrostatic organ avoid sinking only by constant swimmingenabling the animal to remain sus- with the aid of an asymmeterical (heterocerpended in the water at any depth. cal tail.Example sea horse Example Scaliodon.

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Q.35. (a) Give a difference between lizards and snakes. [2011 (T-II)](b) Name the type of nutrition in fungi.

Ans. (a) Lizards have four legs and a long tail, eardrums and movable eyetids. Snakes are limblessreptiles that lack eardrums.

(b) Saprophytic type of nutrition is found in fungi.Q.36. Thallophyta, bryophyta and pteridophyta are classified as cryptogamae whereas gymnosperms

and angiosperms are classified as phanerogamae, why? [2011 (T-II)]Ans. Cryptogams belong to thallophyta, bryophyta and pteridophyta. The reproductive organs in

thallophyta, bryophyta and pteridophyta are hidden and are very inconspicuous. Externalflowers or seeds are not present. The plants in these three groups are therefore called‘cryptogamae’ (cryptos = hidden, gamous = marriage).Gymnosperms and angiosperms are the plant groups with well developed reproductiveorgans which produce seeds. These are called phanerogamae (phaneros = visible, gamous= marriage) as seeds are visible. The seeds may be naked (in gymnosperms) or enclosed infruits (angiosperms).

Q.37. How can we say that sea horse is a fish while jelly fish is not a fish but a coelenterate?[2011 (T-II)]

Ans. Sea horse is a fish because1. It is exclusively adapted to aquatic life.2. The body is covered with scales.3. Body is streamlined.4. Fins are present but limbs are absent.5. Muscular tail is present which is used for movement.6. Respiration is through gills.7. Heart is two-chambered.8. These are cold-blooded animals (the body temperature fluctuates with the temperature of

the environment).9. They lay eggs.

10. It is bony in which the skeleton is made of bones.Q.38. (i) Which group of plants is known as ‘flowering plants’?

(ii) On the basis of seed how a maize plant is different from a pea plant? [2011 (T-II)]Ans. (i) Angiosperms are the most common flowering plants.

(ii) Maize plant is different from a pea plant because in maize seeds contain only onecotyledon in the embryo. While in pea plants seeds contain two cotyledons in the embryo.

Q.39. Give any two reasons why mosses are found in moist and humid places. [2011 (T-II)]Ans. Mosses are found in moist and humid places because they are amphibians of plant kingdom

and amphibious in nature.Q.40. What are gymnosperms? Give two characteristics. [2011 (T-II)]Ans. Gymnosperms include the plants with naked seeds i.e. the seeds are not enclosed in fruits.

Characteristics1. Plants are perennial, evergreen and woody.2. They may be either trees or shrubs.

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Q.41. Write the names of the parts as A, B, C and D given in thefigure in your answer book. [2011 (T-II)]

Ans. A — Snout B — Pectoral finC — Dorsal Fin D — Brood pouch

Q.42. (a) State two characteristic features of nematode.(b) Identify the phylum with the help of following features :(i) Spiny - Skinned, radial symmetrical and have tube feet.(ii) Triploblastic, worm - like, having segmented body. [2011 (T-II)]

Ans. (a) Features of Nematode1. They have narrow, elongated and cylindrical bodies.2. They have narrow, elongated and cylindrical bodies

(b) (i) — Echinodermata (ii) — AnnelidaQ.43. Who proposed the five kingdom classification? What is the basis of this classification?

[2011 (T-II)]Ans. Robert H. Whittaker, an American taxonomist in 1969 was the first one to propose a five–

kingdom classification based on (i) cell structure, (ii) mode and source of nutrition, and (iii)body organisation.

Q.44. Label X and Y in the given diagram of Hydra. [2011 (T-II)]

Ans. X — Tentacles, Y — FootQ.45. Give one example of each :

(a) Reptile which has a four chambered heart.(b) Egg - laying mammal.(c) Parasitic Platyhelminthes(d) Division among plants which has the simplest organisms. [2011 (T-II)]

Ans. (a) Crocodile (b) Echidna (c) Planaria (d) ThallophytaQ.46. Identify the phylum for the following characteristics given :

(a) Organisms with joint appendages.(b) Organisms are generally flatworms

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(c) Body is segmented(d) Skin of organisms is full of spikes [2011 (T-II)]

Ans. (a) Arthropoda (b) Platyhelminthes (c) Annelida (d) ReptilesQ.47. Write any two characteristics of class mammalia. Name one egg laying mammal.

[2011 (T-II)]Ans. Characteristics of Mammalia

1. Warm – blooded animals.2. Mammals have two pairs of pentadactyl limbs. Egg laying mammal is Platypus

Other Important QuestionsQ.1. Answer the following :

(i) Who is known as the ‘Father of Taxonomy’?(ii) What is meant by nomenclature?

Ans. (i) Carolus Linnaeus(ii) The system of naming living and nonliving objects is called nomenclature.

Q.2. Write the contribution of Haeckel and Whittaker in classification.Ans. E.H. Haeckel raised third kingdom named protista for unicellular eukaryotic organisms.

Whittaker proposed five kingdom classification based on cell structure (prokaryotic/eukaryotic), mode of nutrition and body organisation.

Q.3. Name the group of plants with the following characters :(a) Plants with seeds(b) Plants without roots, stem, leaves or flowers(c) Plants having seeds with two cotyledons(d) Plants visible with naked eye but having no chlorophyll

Ans. (a) Phanerogams (b) Thallophyta(c) Dicotyledons (d) Fungi

Q.4. You are provided with the seeds of gram, wheat, rice and pumpkin. Classify them whether theyare monocot or dicot.

Ans. (a) Gram — Dicot (b) Wheat — Monocot(c) Rice — Monocot (d) Pumpkin — Dicot

Q.5. Distinguish between Bryophyta and Pteridophyta.

Ans. Bryophyta Pteridophyta

(i) The plant body is not differentiated (i) The plant body is differentiated intointo root, stem and leaves. root, stem and leaves.

(ii) Vascular tissues are absent. (ii) Vascular tissues are present.(iii) Sex organs are simple and single-celled. (iii) Sex organs are multicellular.(iv) After fertilisation, no embryo (iv) Embryo is formed after fertilisation.

formation takes place.

Q.6. What are vascular cryptogams?Ans. (a) These are green autotrophic plants in which vascular tissues are present.

(b) The dominant plant body is differentiated into root, stem and leaves.

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(c) Sex organs are multicellular.(d) Embryo is formed after fertilisation.

Q.7. Write any four differences between dicotyledons and monocotyledons.

Ans. Monocotyledons Dicotyledons

(i) These bear seeds with single cotyledon. (i) These have two cotyledons.(ii) These have parallel venation. (ii) These have reticulate venation.

(iii) Vascular bundles are arranged in (iii) Vascular bundles are arranged in a ring.complex manner.

(iv) These have fibrous root system. (iv) These have tap root system.

Q.8. Name the phylum to which each of the following animals belong:Seahorse, Silverfish, Jellyfish, Cuttlefish.

Ans. Seahorse — PiscesSilverfish — ArthropodaJellyfish — CnidariaCuttlefish — Mollusca

Q.9. Give two characters of bryophytes.Ans. Two characteristics of bryophytes are

(i) The plant body is not differentiated into root, stem and leaves.(ii) They are non vascular plants.

Q.10. How is classification and evolution interrelated with each other?Ans. Despite of diversity, the living organisms are interrelated bacause of their common origin. If

we study different groups of living organisms, they exhibit hierarchial complexity. Darwinexplained evolution as ‘Descent with modification’. It means all species are formed by themodifications of pre existing ones. Thus, the gradual increase in complexity in living organ-isms, not only confirm the concept of evolution but also tells interrelation between variousorganisms.

C. Short Answer Questions - II (3 Marks)

Previous Years' Questions

Q.1. List three groups of plants. Which plants are referred to as vascular plants? Out of these whichgroup is further classified on the basis of number of cotyledon? State its two characteristics.

Ans. Three groups of plants are(i) Angiosperms (ii) Bryophyta (iii) PteridophytaPteridophytes are referred to as vascular plants. Out of these angiosperms plants can be furtherclassified on the basis of number of cotyledon.Characteristics1. They are seed bearing plants, i.e., seeds are enclosed inside the fruit formed.2. Dominant group of land plants and most common flowering plants.

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Q.2. List in the tabular form any three differences between the Aves and the Mammalia group.[2011 (T-II)]

Ans. Aves Mammalia

(a) Feathered animals body is covered with (a) Skin is covered with hair.feathery exoskeleton.

(b) The body is divisible into head, neck, (b) The body is divided into head, thoraxtrunk and tail. and abdomen.

(c) They are oviparous i.e., egg laying. (c) They are viviparous i.e., give birth toyoung ones.

Q.3. Identify the plant bodies, which are commonly named as ‘cryptogamae’. State and explain twocharacteristics, which are exhibited by each category of these plant bodies. [2011 (T-II)]

Ans. Plant bodies which are commonly named as ‘cryptogamae’ are(i) Thallophyta (ii) Bryophyta (iii) Pteridophyta(A) Thallophyta (Thallas) = undifferentiated, phyta = plant(i) The plant body is not differentiated into root, stem and leaves.(ii) Vascular tissues are absent.(B) Bryophyta (Bryon = mass, Phyta = plant)(i) The plant body is either thallus – like (thalloid) or leaf – like (foliose).(ii) The plant body is green and autotrophic.(C) Pteridophyta (Pterid – fern, phyton – plant)(i) They are highly evolved ferns.(ii) Stem is generally underground.

Q.4. (i) Draw a neat diagram of Hydra. [2011 (T-II)](ii) Label mesoglea and gastrovascular cavity.

(iii) Name the group of animals it belongs to.(iv) Name one species of this group that lives in colonies.

Ans. (i) Diagram of Hydra(ii) Labelling

(iii) It belongs to the group Cnidaria of Phylum – Coelenterata(iv) Corals

Q.5. In the given classification scheme fill in the boxes with appropriate plant groups :[2011 (T-II)]

Ans. For Flow-chart See Q.3 Pg.-75Q.6. Define the terms and give one example of each

(i) Bilateral symmetry (ii) Coelom (iii) Triplobastic [2011 (T-II)]Ans. (i) Bilateral symmetry – When the body of an organism can be cut into similar halves which

are mirror images of each other, only by one plane. Example – man(ii) Coelom – Body cavity of tripoblastic animals lying within the mesoderm and lined by it.

Example – Annelida

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(iii)Triploblastic – Animals having a body made of three germ layers : ectoderm, mesodermand endoderm. Example – Fasciola (liver fluke)

Q.7. Write any three differences between Amphibia and Mammalia belonging to kingdomAnimalia.

Ans. Amphibia Mammalia

(a) Amphibious in nature, i.e., found in (a) Mammals are the most evolved groupwater and on land both. of organisms found in diverse habitats

ranging from deserts, polar ice caps.(b) Head and trunk distinct. (b) The body is divided into head, thorax

and abdomen.(c) Heart is three chambered. (c) Heart is four chambered.

Q.8. Pick the odd one out and justify your choice by giving reasons. [2011 (T-II)](a) Moss, Fern, Pinus, Spirogyra.(b) Sea Cucumber, Octopus, Feather Star, Star fish. [2011 (T-II)]

Ans. (a) Spirogyra — It is a thallophyte, the body is not differentiated into root, stem and leaves.(b) Octopus — It is a mollusc. The body is soft, unsegmented, triploblastic, coelomate animal.

Q.9. Identify the following diagrams. Write the phylum do they belong to? Write down the char-acteristic features of each phylum. [2011 (T-II)]

Ans. Phylum Annelida1. They are triploblastic animals having bilateral symmetry.2. Alimentary canal is complete.3. Respiration takes place through the general body surface.

Phylum Porifera1. They are exclusively aquatic in their habitat, mostly

marine.2. Nervous and sensory cells are absent.3. Respiration and excretion take place through general

body surface.Q.10. (a) Write down the four characteristic features of the members of the class Aves.

(b) To which group do the following belong : [2011 (T-II)](i) Evergreen trees that bear naked seeds.(ii) Plants which have tap root system and two cotyledons in their seeds.

Ans. (a) Characteristics of class Aves1. The heart is four – chambered.2. They are warm – blooded animals.3. Respiration is by lungs only.4. Sexes are separate.

(b) (i) Gymnosperms (ii) Dicotyledonae.Q.11. Name the group which is called ‘Amphibians of Plant kingdom’. Cite an example of this group

also mention one important feature of the same group. [2011 (T-II)]Ans. Bryophytes are the Amphibians of Plant kingdom. Example Marchantia

One important feature of this group is they lack true vascular tissue.

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Q.12. On the basis of the following features, identify the group and giveone example of each :(i) Presence of notocord at some stage of life.

(ii) Unicellular, microscopic and eukaryotic.(iii) Seeds are enclosed in fruits. [2011 (T-II)]

Ans. Group Example

(i) Vertebrata humans

(ii) Protista protozoa

(iii) Angiosperms mustardQ.13. (a) Draw a well labelled diagram of Euglena.

(b) Name the kingdom to which it belongs. [2011 (T-II)]Ans. (a) Diagram of Euglena

(b) Euglena belongs to kingdom ProtistaQ.14. Differentiate between annelida and nematode. [2011 (T-II)]Ans. Annelida Nematode

(a) The body is composed of rings or (a) They have narrow, elongated andsegment-showing metameric cylindrical body.segmentation.

(b) Body is soft, no hard skeleton. (b) They are triploblastic, unsegmentedanimals with bilateral symmetry.

(c) True body cavity is present. (c) Body cavity is not a true coelom; it iscalled pseudocoel or pseudocoelom.

(d) Blood vascular system is of closed (d) Respiratory, circulatory and skeletaltype. systems are absent.

Q.15. What is the importance of classification? [2011 (T-II)]Ans. Importance of Classification

1. Classification serves as a base for all other disciplines of biology.2. It allows easy means of communication of information to other people.3. Classification is an information storage system and the biologists need it for the specific

organism they work with.4. Classification projects before us a picture of all life forms at a glance.5. Classification tells us about the interrelationships between different groups of organisms,

and in turn provides us information about their evolution.6. Classification makes the study of the wide variety of organisms existing in the living

world convenient, easy and time – saving.7. Various fields of applied biology such as agriculture, environmental biology and public

health depend on the correct identification and classification of disease causing organismsand insect pests.

Q.16. (a) In which two ways are amphibians differed from fishes?(b) Identify the phylum of organisms having the following characteristics.

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(i) Pore bearing animals and radial symmetry(ii) Body spiny and radial symmetry

(c) Why gymnosperms do not require water for fertilization? [2011 (T-II)]Ans. (a) Amphibians Fishes

1. Heart is three chambered. 1. Heart is two-chambered.2. Skin is smooth or rough but without scale. 2. The body is covered with scale.

(b) (i) Phylum Porifera(ii) Phylum Echinodermata

(c) Gymnosperms does not require water for fertilization because inGymnosperms fertilization occurs by wind.

Q.17. (a) Name the phylum to which each of the following animals belongs to, Silver fish, Starfish,Tapeworm, Leech. [2011 (T-II)]

(b) List two features of vertebrates.Ans. Animal Phylum

(a) Silver fish — EchinodermataStar fish — EchinodermataTapeworm — PlatyhelminthesLeech — Annelida

(b) Two features of vertebrates are(i) Triploblastic and coelomate

(ii) Presence of a tubular, dorsal, hollow nerve cordQ.18. To which group do the following organism belong and give one reason for each.

[2011 (T-II)](a) Cyanobacteria (b) Euglena (c) Ulothrix

Ans. (a) Cyanobacteria – belongs to the group Monera because these organisms are prokaryotici.e., they do not have a defined nucleus and lack cell organelles.

(b) Euglena – belongs to the group Protista because organisms in this kingdom areunicellular, eukaryotic organisms (as well - defined nucleus and other cell organelles arepresent).

(c) Ulothrix – belongs to the group Thallophyta because vascular tissues are absent.Q.19. (i) What are vertebrates? [2011 (T-II)]

(ii) Name four sub groups of vertebrates.Ans. (i) Vertebrates are a large group of animals comprising all those members of the phylum

Chordata that have backbones.(ii) Four sub groups of vertebrates are

1. Pisces 2. Amphibia 3. Reptilia 4. AvesQ.20. Write one difference for each of the following pairs. [2011 (T-II)]

(i) Thallophyta and Bryophyta (ii) Nematoda and Annelida (iii) Amphibia and Reptilia

Ans. (i) Thallophyta Bryophyta1. Embryo formation after fertilization is 1. Embryo – stage present.

absent.

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(ii) Nematoda Annelida

1. Body cavity is not a true coelom, it is 1. True body cavity is present.called pseudocoel or pseudocoelom.

(iii) Amphibia Reptilia1. Amphibious in nature i.e., found in 1. Truly terrestrial animals.

water and on land both.

Q.21. Differentiate between the following , giving one main point of difference. [2011 (T-II)](a) Gymnosperm and Angiosperm(b) Diploblastic and Triploblastic animals(c) Dicotyledons and Monocotyledons.

Ans. (a) Gymnosperm Angiosperm

1. Naked seeded plants-seeds are not 1. Seed bearing plants i.e., seeds areemclosed within the fruit. enclosed inside the fruit formed.

(b) Diploblastic Triploblastic

1. Animals having two germ layers–the 1. Animals having three germ layers–ectoderm and endoderm are called the ectoderm, mesoderm anddiplablastic animals. endoderm are called triploblastic

animals.

(c) Monocotyledons Dicotyledons

1. Vascular bundles are arranged in 1. Vascular bundles are arranged in acomplex manner. ring.

Q.22. (a) List any two main characteristics of chordates. [2011 (T-II)](b) In which class would you place any organism which has —

(i) four chambered heart and lay eggs.(ii) skeletons made of both bones and cartilage and are cold blooded.

Ans. (a) Two main characteristics of chordates are1. Presence of an unsegmented, elastic, rod-like structure called notochord.2. Presence of pharyngeal gill slits.

(b) (i) Mammals. (ii) FishQ.23. Name the phylum to which this organism belongs. Write any

two characteristic feature of the phylum. [2011 (T-II)]

Ans. This organism belongs to phylum Mollusca.Characteristics1. Bilateral symmetry is present.2. Respiration occurs through gills called ctenidia.

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Q.24. Classify the following organisms based on the absence / presence of true coelom i.e. acoelo-mate, pseudocoelomate and coelomate) [2011 (T-II)]

(a) Scorpion (b) Sea anemone(c) Ascaris (d) Earthworm(e) Wuchereria (f) Nereis

Ans. (a) Scorpion – Coelomate (b) Sea anemone – Acoelomate(c) Ascaris – Pseudocoelomate (d) Earthworm – Coelomate(e) Wuchereria – Pseudocoelomate (f) Nereis – Coelomate

Q.25. Write the most striking features of the following phyla : [2011 (T-II)](i) arthropoda (ii) amphibia (iii) porifera

Ans. (i) Arthropoda – The arthopods are the most successful group of animals. They are thelargest group of animals in total number of species, being represented by more than700,000 species (nearly 80% of the animal kingdom).

(ii) Amphibia – The amphibians are the first land vertebrates, but they are partly terrestrialand partly aquatic.

(ii) Porifera – They are very simple and sessile organisms and are the simplest amongst themulticellular animals. They consist of colonies of cells, lacking organs.

Other Important QuestionsQ.1. Classify the following organisms based on the absence/presence of true coelom (i.e., acoelo-

mate, pseudocoelomate and coelomate)

Spongilla Sea anemone, Planaria Liver fluke

Wuchereria Ascaris, Nereis, Earthworm

Scorpion Birds, Fish, Horse.

Ans. Acoelomate Pseudocoelomate Coelomate

Planaria, Liver fluke Wuchereria, Ascaris Earthworm, NereisSea anemone, Spongilla

Q.2. Endoskeleton of fish are made up of cartilage and bone; classify the following fish ascartilagenous or bony Torpedo, Sting ray, Dog fish, Rohu, Angler fish, Exocoetus.

Ans. Cartilaginous fish Bony fish

Torpedo, Sting ray, Dog fish Rohu, Angler fish, Exocoetus

Q.3. Classify the following based on number of chambers in their heart.Rohu, Scoliodon, Frog, Salamander, Flying lizard, King Cobra, Crocodile, Ostrich,Pigeon, Bat, Whale.

Ans. Types of animals based on heart chambers

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Two-chambered Three-chambered Incompletely Four-chambered Four-chambered

Rohu, Scoliodon Frog, Salamander Flying lizard, King Cobra Crocodile, Ostrich,Pigeon, Bat, Whale

Q.4. Classify Rohu, Scoliodon, Flying lizard, King Cobra, Frog, Salamander, Ostrich, Pigeon, Bat,Crocodile and Whale as the cold blooded/warm blooded animals.

Ans. Cold-blooded Animals Warm-blooded Animals

Rohu OstrichScoliodon PigeonFlying lizard BatKing Cobra WhaleSalamander

Q.5. Match items of column (A) with items of column (B)

(A) (B)

(a) Pore bearing animals (A) Arthropoda(b) Diploblastic (B) Coelenterata(c) Metameric segmentation (C) Porifera(d) Jointed legs (D) Echinodermata(e) Soft bodied animals (E) Mollusca(f) Spiny skinned animals (F) Annelida

Ans. Column (A) Column (B)

(a) Pore-bearing animals (C) Porifera(b) Diploblastic (B) Coelenterata(c) Metameric segmentation (D) Annelida(d) Jointed leg (A) Arthropoda(e) Soft-bodied animals (E) Mollusca(f) Spiny skinned animals (F) Echinodermata

Q.6. What is the difference between the following :(a) The heart of a fish and that of a bird(b) Breathing organs of fish and lizard(c) The position of mouth in shark and salmon.

Ans. (a) Heart of fish Heart of bird

(i) Fish have 2-chambered heart. (i) Birds have 4-chambered heart.

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(b) Breathing organ of fish Breathing organ of lizard

(i) Breathing organs are gills. (i) Breathing organs are lungs.

(c) Position of mouth in shark Position of Mouth in salmon

(i) Mouth is present on ventral side. (i) Mouth is terminal or subterminal.

Q.7. Label a, b, c and d, given in figure. Give the function of (b).

Ans. (a) Dorsal fin (b) Caudal fin (c) Anal fin (d) Pelvic fin.The caudal fin helps in different directional movements.

Q.8. Fill in the boxes given in figure with appropriate characterstics/plant group(s)

Ans. (a) Thallophyta (b) Without vascular tissues (c) Pteridophyta (d) Phanerogams(e) Bear naked seeds (f) Angiosperms (g) Have seeds with two cotyledons (h) Monocots

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D. Long Answer Questions (5 Marks)

Q.1. Thallophyta, bryophyta and pteridophyta are called as ‘Cryptogams’. Gymnosperms andangiosperms are called as ‘phanerogams’. Discuss why?

Ans. Cryptogams belong to thallophyta, bryophyta and pteridophyta. The reproductive organs inthallophyta, bryophyta and pteridophyta are hidden and are very inconspicuous. Externalflowers or seeds are not present. The plants in these three groups are therefore called‘cryptogamae’ (cryptos = hidden, gamous = marriage).Gymnosperms and angiosperms are the plant groups with well developed reproductiveorgans which produce seeds. These are called phanerogamae (phaneros = visible, gamous= marriage) as seeds are visible. The seeds may be naked (in gymnosperms) or enclosedin fruits (angiosperms).

Q.2. You are given leech, Nereis, Scolopendra, prawn and scorpion; and all have segmented bodyorganisation. Will you classify them in one group? If no, give the important characters basedon which you will separate these organisms into different groups.

Ans. No, all these animals will not be classified into one group despite of all having segmented body.Leech and Nereis belong to phylum annelida.(i) Body is metamerically segmented, i.e; divided into small segments externally by ver-

tical partitions called septa.(ii) The body is bilaterally symmetrical, triploblastic with true body cavity.

(iii) Respiration takes place by general body surface.(iv) Excretion occurs through coiled tubular structures called nephridia.Scolopendra, prawn and scorpion belong to phylum arthropoda.

(i) Unlike annelids, segments are not separated by septa. Segments are grouped to formthree parts, i.e; head, thorax and abdomen.

(ii) Respiration occurs through gills, trachea or book lungs.(iii) These have jointed legs.(iv) The body is covered by a hard exoskeleton made of chitin.

Q.3. Which organism is more complex and evolved among bacteria, mushroom and mango tree.Give reasons.

Ans. Among bacteria, mushroom and mango tree, mango tree is more complex and evolved.Bacteria are unicellular, simple, microscopic organisms. They lack nuclear membrane andchlorophyll. Cell organelles are absentMushrooms are non-green plants. Their body is a web of fine, delicate thread-like hyphae.Mango tree belongs to Angiosperms. Their body is highly developed and differentiated intoroots, stem, leaves, flowers and fruits. They prepare their own food. All cellular organellesare present.Based on these properties, we can say that mango tree is more complex and evolved incompared to bacteria and mushroom.

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Q.4. Differentiate between flying lizard and bird.

Ans. Flying Lizard Bird

(i) It belongs to class Reptilia. (i) It belongs to class Aves.(ii) Its skin is rough and dry. (ii) Its skin is covered with feathers.

(iii) Cold-blooded animal. (iii) Warm-blooded animal.(iv) Two pairs of pentadactyl (iv) There are two pairs of limbs but the fore

limbs are present. limbs are modified to wings.(v) Heart is incompletely (v) Heart is completely divided into four

divided into four chambers. chambers.

Q.5. How can we keep mosquito and prawn in the same group?Ans. Prawn and mosquito both are kept in arthropoda group because :

(i) The body of mosquito is divided into head, thorax and abdomen. In case of Prawn, headand thorax are fused to form cephalothorax.

(ii) They have six or more jointed appendages.(iii) The body is covered by a hard exoskeleton made of chitin.(iv) Prawn belongs to class crustacea of arthropoda and mosquito belongs to class insecta of

arthropoda.(v) Compound eyes having many lenses are present. They therefore have mosaic vision.

II. FORMATIVE ASSESSMENT

A. Quiz

Q.1. During a practical examination Pankaj was asked to identify a plant cell and an animal cellcorrectly by looking through two microscopes. They looked alike.How can he identify them correctly?

Ans. Plant Cell Animal Cell

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Major differences between Animal and plant cells

S.No. Animal cell Plant cell

(i) Cell wall – absent. Cell wall – present.

(ii) Plastids – absent. Plastids – present.

(iii) Vacuoles – generally absent, if present they Vacuoles – generally present but only oneare more in number and smaller in size. large vacuole is present.

(iv) Centrosomes with centrioles present. Centrosomes and centrioles are absent,instead polar caps present.

Q.2. Complete the table :

Across(i) Plants having a single cotyledon.

(ii) A mammal which digs hole in the ground.(iii) Heterotrophic eukaryote which uses de-

caying organic material as food.(iv) An aquatic alga containing chlorophyll.

Down(v) The phylum to which earthworm belongs.

(vi) The kingdom in which organisms do nothave a defined nucleus or organelles anddo not show multicellular body designs.

(vii) Scientific name of starfish.(viii) Whip like appendages in Euglena.

Ans.

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