007 Diversity in Living Organsims

07 Diversity In Living Organisms INTRODUCTION All living organisms vary in their forms, structure and mode of life. This uniqueness is due to diversity in the life forms. On the basis of similarities and dissimilarities, all the organisms are classified, i.e., divided into groups and sub-groups. Thus, classification is the method of rearranging and regrouping of organisms into various groups or sets on the basis of similarities and differences. The science of classification is known as taxonomy. Biologist named Whittaker proposed that all living organisms can be classified into five broad categories or kingdoms— Monera, Protista, Fungi, Plantae and Animalia. Further classification is done by naming subgroups at various levels as species, genus, family, order, class, phylum for animals and division for plants. IMPORTANT TERMS AND CONCEPTS 1.

Basis of Classification : The use of important distinguishing features forms the basis of classification. The similar characters, i.e., similarities enable us to group living things together. The different characters, i.e. dissimilarities separate them. Thus, similarities and dissimilarities form the basis of classification. The characteristics of body design used for classification of plants will be very different from those important for classifying animals. This is because the basic designs are different, based on the need to make their own food (plants) or acquire it (animals). Thus, these design features are to be used to make sub-groups, rather than making broad groups.

2.

Importance of Classification : The science of classification is an important branch of biological science. Classification of living organisms has the following advantages: (i) Classification makes the study of a wide variety of organisms convenient and easy. (ii) It projects before us a picture of all life forms at a glance. (iii) It helps us to understand the interrelationships among different categories of organisms and thus provides us information about their evolution. (iv) All biological sciences depend upon a system of classification for study of organisms, e.g., biogeography, ecology, pathology, forestry. (v) Classification gives a system for identification of known and unknown organisms.

3.

Classification and Evolution: The idea that all present day forms have been developed due to accumulation of changes in body design is contained in the concept of evolution as proposed by Charles Darwin (1859) in his book The Origin of Species'. The concept of evolution shows that— (i) Some groups of organisms have ancient body design which has not much changed. (ii) Some groups of organisms have developed a particular body design only recently, e.g., primates. (iii) Primitive or older organisms are simpler while the recent or younger organisms are more complex.

4.

Biodiversity : It means the diversity of forms. Biodiversity is the existence of a wide variety of species or other taxa of plants, animals and micro-organisms in a natural habitat within a particular environment.

5.

Region of Megadiversity : It is the region of warm and humid tropical regions of the, earth, between the Tropic of Cancer and the Tropic of Capricorn, where there is rich diversity of plant and animal life.

6.

Hierarchy: It is a system of arrangement or framework for classification in which taxonomic categories are placed in order of logical sequence.

7.

Taxon : It is defined as a unit of classification of organisms which can be recognized to a definite category at any level of classification, e.g., fishes, insects, etc.

8.

Taxonomic Categories : These are ranks or grouping of organisms developed in any system of classification on the basis of their fundamental similarities and dissimilarities. The important taxonomic categories are Kingdom, Division/Phylum, Class, Order, Family, Genus and Species.

9.

Hierarchy of Classification: • Biologists such as Ernst Haeckel, Robert Whittaker and Carl Woese have tried to classify all living organisms into broad categories called Kingdoms. • The classification proposed by Whittaker has five kingdoms : Monera, Protista, Fungi, Plantae and Animalia and is widely used. • These groups are formed on the basis of their cell structure, mode and source of nutrition and body organisation. • The taxa of living organisms are ranked in a hierarchy of categories as follows : Kingdom — Animalia Phylum/Division — Chordata Class — Mammalia Order — Primata Family — Hominidae Genus — Homo Species — sapiens • Here, scientific name of Human beings is Homo sapiens. • Thus, we reach the basic unit of classification, i.e., 'species' by separating organisms on the basis of a hierarchy of characteristics into smaller and smaller groups.

10.

Species : It is a group of organisms capable of interbreeding to produce fertile offspring. Species is the lowest or the basic taxonomic category, e.g., Solanum tuberosum (Potato).

11.

Genus: It is a group of closely related species that forms a taxonomiccategory higher than species, e.g., dog, jackal and wolf are placed in the same genus Canis.

12.

Family : A number of genera having several common characters that form a family, e.g., Solanum and Datura have some characters in common, so they are placed in same family Solanaceae.

13.

Order : A number of families having common characters are placed in an order, e.g., cat, tiger, etc. belong to family Felideae.

14.

Class : The similar orders are placed together in a class, e.g., Class Mammalia includes orders like Carnivora, Chiroptera, Primata and Rodentia.

15.

Phylum : Many classes with some own specific common characters are included in a phylum or division, e.g., Phylum-Chordata Division-Bryophyta. The term phylum is commonly used for animals and division for plants.

16.

Kingdom : It is the highest category of taxonomic studies. All animals are included in animal kingdom and all plants are included in plant kingdom, e.g., Kingdom—Monera. Each Kingdom is fundamentally different from any other such category but has the same fundamental characteristics in all the organisms grouped under that kingdom.

17.

Five Kingdom Classification : Robert Whittaker (1959) has classified all the living organisms into following five kingdoms : (i) Kingdom Monera : Unicellular, Prokaryotes like bacteria, blue-green algae and mycoplasma. (ii) Kingdom Protista: Unicellular, Eukaryotes like protozoans and algae. (iii) Kingdom Fungi: Multicellular, Eukaryotic non-green heterotrophs lacking chlorophyll and having absorptive mode of nutrition like mushrooms and moulds. (iv) Kingdom Plantae : Multicellular, Eukaryotic green plants containing chlorophyll having autotrophic mode of nutrition like algae, mosses, ferns and flowering plants. (v) Kingdom Animalia : Multicellular, Eukaryotic heterotrophic animals lacking chlorophyll and having ingestive mode of nutrition like corals, insects, earthworms, birds, reptiles and mammals. The Five Kingdom Classification can be represented in terms of cell structure as follows:

Whittaker based his scheme of classification on the following three levels of organisation : (i) Prokaryotic versus Eukaryotic cell structure. (ii) Three different modes of nutrition— Photosynthesis (plants), Absorption from the environment (fungi) and Ingestion (animals). (iii) Unicellular versus Multicellular organisation. 18.

Kingdom Monera: • These organisms are prokaryotic, i.e., they do not have a well-defined nucleus and lack cell organelles. • Some of the organisms have cell walls (like bacteria and blue-green algae), while others lack cell walls (mycoplasma). • Mode of nutrition is either autotrophic (as in blue-green algae and some bacteria) or heterotrophic (mycoplasma and most bacteria). Examples : Bacteria, blue-green algae or cyanobacteria and mycoplasma.

19.

Kingdom Protista : • These organisms are unicellular and eukaryotic {as well defined nucleus and other cell organelles are present).

• Mode of nutrition is either totrophic (as in algae and diatoms) or heterotrophic (as in protozoans). • Some of the organisms use appendages such as hair-like cilia or whip-like flagella for movement. In some protists like Amoeba, movement takes place by pseudopodia (false feet). Examples : Algae, diatoms , Euglena and protozoans (Amoeba).

20.

Kingdom Fungi : • Fungi are eukaryotic non-green (lacking chlorophyll) organisms. • They are heterotrophic in nutrition and obtain food from decaying organic matter and so called saprophytes. • Many become multicellular organisms at certain stages in their lives. • They have cell wall made of a tough complex sugar called chitin. • Some fungi live in symbiotic (mutually dependent) relationships with blue-green algae as in lichens. Examples: Yeast, Agaricus (Mushroom), Aspergillus, Penicillium.

21.

Kingdom Plantae: • These are multicellular eukaryotes with cellulose cell walls. • They are autotrophs and use chlorophyll (present in chloroplasts) for photosynthesis. • All plants are included in this group forming visible forms of biodiversity. • The first level of classification among plants depends on whether the plant body has well differentiated, distinct components (like root, stem, leaf, etc.). • The next level of classification is based on whether the differentiated plant body has vascular tissues for the transport of water and other substances within it. • Further classification is based on the ability to bear seeds and whether the seeds are enclosed within fruits.

22.

• Kingdom Plantae thus consists of Thallophyta, Bryophyta, Pteridophyta, Gymnosperms and Angiosperms. Classification of Kingdom Plantae (Plants) :

23.

Thallophyta (Thallus—undifferentiated, phyta—plant): • Plants do not have well-differentiated body design. • The plants in this group are commonly called algae. • These plants are predominantly aquatic. • Algae are green thallophytes (autotrophic) that contain chlorophyll. Examples: Algae (Spirogyra, Ulothrix, Cladophora and Chard).

24.

Bryophyta (Bryon—moss, phyta—plant):

• They are the first plants to live on land and in water and are therefore, called the amphibians of the plant kingdom. • The plant body is differentiated to form stem and leaf-like structures. • There is no specialised tissue for the conduction of water and other substances from one part of the plant body to another. Examples: Moss (Funaria) and Liverworts (Riccia, Marchantia).

25. Pteridophyta : • They are the first land plants having vascular tissues. • The plant body is differentiated into roots, stem and leaves. • They have specialised tissue for the conduction of water and other substances from one part of the plant body to another.

26.

Cryptogamae (Crypto—hidden, gamous—marriage): • The reproductive organs in the thallophytes, the bryophytes and the pteridophytes are hidden and are very conspicuous. • External flowers or seeds are absent and they have naked embryos called spores. • The plants in these three groups are therefore, called 'cryptogamae'.

27.

Phanerogamae (Phaneros—visible):

• Plant groups with well-developed reproductive organs, which produce seeds are called 'phanerogamae'. • Seeds consist of the embryo along with stored food which provides nutrition to the growing embryo. • This group is classified into two sub-groups—gymnosperms and angiosperms, based on whether the seeds are naked or enclosed in fruits. 28.

Gymnosperms (Gymno—naked, sperma—seed): • These are naked-seeded plants, i.e., seeds are not enclosed within a fruit. • The plants of this group are usually perennial, evergreen and woody. • The flowers are represented by unisexual cones, both being present on the same plant. Examples : Pinus (Pines), Cycas.

29.

Angiosperms {Angio—covered): These are the most common flowering plants. • The angiosperms are seed-bearing plants and the seeds develop inside an organ which is modified to become a fruit. • Plant embryos in seeds have structures called 'cotyledons'. • 'Cotyledons' are called 'seed leaves' because they emerge and become green when the seed germinates. • Angiosperms are divided into two groups on the basis of the number of cotyledons present in the seed. (i) Monocotyledonous or monocots: They are the plants with seeds having a single cotyledon, e.g., maize, wheat, rice, etc. (ii) Dicotyledonous or dicots: They are plants with seeds having two cotyledons, e.g., pea, gram, bean, etc.

30.

Kingdom Animalia : • These are multicellular eukaryotes without cell walls. • They are heterotrophic in their mode of nutrition. • Kingdom Animalia or animals are further classified based on the extent and type of the body design differentiation found. • They are classified as Porifera, Coelenterata, Platyhelminthes, Nematoda, Annelida, Arthropoda, Mollusca, Echinodermata, Protochordata and Vertebrata.

31.

Classification of Kingdom Animalia (Animals)

32.

Phylum Porifera (organisms with holes—the sponges): • They are the simplest multicellular animals and mostly marine except Spongilla. • The sponges are 'pore-bearing' animals with canal systems. • They are non-motile animals attached to some solid support. • The characteristic canal system of the body helps in circulating water throughout the body to bring in food and oxygen. • The animals are covered with a hard outside layer or skeleton. • The body design involves minimal differentiation and division into tissues.

• Most of the sponges are asymmetrical with some radially asymmetrical. • The body is porous, the pores are called ostia. There is a single large opening called the osculum. • Porifera is the only phylum of multicellular organisms whose members lack a nervous system. Examples : Sycon, Spongilla, Euplectella, etc. 33.

Phylum Coelenterata (means hollow gut): • These animals live in water. • Coelenterates show more body design differentiation. • The body has a sac-like body cavity with a single opening to the outside for ingestion and egestion. • These are the first of multicellular animals which possess tissue level organisation with a distinct division of labour. • The body is made of two layers of cells—one makes up cells on the outside of the body and the other makes the inner lining of the body. • Some of the species live in colonies (corals), while others have a solitary life-span (Hydra). Examples : Hydra, Obelia, Aurelia (Jelly fish), Metridium (Sea anemone).

34.

Phylum Platyhelminthes (Flat worms) : • They are mostly parasitic animals (living in the bodies of other animals) like liverflukes and some are free-living like Planaria. • They are the first simplest triploblastic animals, i.e., having three layers of cells from which differentiated tissues can be made. • The body is bilaterally symmetrical, meaning that the left and the right halves of the body have the same design. • Body cavity or coelom is absent. • The body is dorsoventrally flattened, meaning from top to bottom so they are called flatworms. Examples: Planaria, Fasciola (Liverfluke), Taenia solium (Tapeworm).

35.

Phylum Nematoda (Thread or Roundworms); • They are parasitic worms causing diseases such as elephantiasis (filarial worms) or the worms in the intestines (roundworms). • The nematode body is bilaterally symmetrical and triploblastic. • Body is elongated, narrow and cylindrical. • There are tissues, but no real organs. • Body cavity is not a true coelom, it is called pseudocoelom.

• These are the first animals to have a complete and straight alimentary canal. Examples : Ascaris, (roundworm), Wuchereria (filarial worm) 36.

Phylum Annelida (Segmented worms) : • These animals are found in a variety of habitats—fresh water, marine water as well as land. • They are bilaterally symmetrical, triploblastic animals. • Annelids are the first animals with true body cavity. • They have metameric segmentation with extensive organ differentiation. The segments of the body are lined up one after the other from head to tail. Examples : Pheretima (Earthworm), Hirudinaria (Leech), Nereis.

37.

Phylum Arthropoda (animals with jointed legs): • Arthropoda is the largest group of animals. • They have segmented body which is divided into three regions—head, thorax and abdomen. • They have jointed legs (3 or more pairs) and a pair of compound eye on the head. • The body is bilaterally symmetrical. • They are found everywhere on the earth—on land, in soil and in water and as parasites on plants and other animals. • The body is covered by a hard exoskeleton made of chitin. • The coelomic cavity is blood-filled. • Open circulatory system is present. Examples: Palaemon (Prawn), Scorpion, Spider, Butterfly, Periplaneta (Cockroach), Musca (Housefly), Apis (Honey bee), Anopheles (Mosquito), Bombyx (Silk moth),

38.

Mollusca (Soft-bodied animals) : • They are mostly aquatic, living in sea water; some occur in fresh water. • Bilateral symmetry is present. • The coelomic cavity is reduced and there is little segmentation. • They have an open circulatory system and kidney-like organs for excretion. • The soft body is supported by a hard shell. • The body is divided into an anterior head, a ventral muscular foot and a dorsal visceral mass. • Locomotion is brought about by muscular foot. Examples: Chiton, Octopus, Pila, Unio, Sepiat Loligo.

39.

Phylum Echinodermata (Spiny-skinned animals): • They are exclusively free-living marine animals. • Body is triploblastic and has a coelomic cavity. • They have a peculiar water-driven tube system that they use for moving around.

• They have hard calcium carbonate structures that they use as a skeleton. • Symmetry is radial in adults but bilateral in larvae. • There is no head or tail, no left or right side. Examples: Asterias (Starfish), Echinus (Sea urchin), Holothuria (Sea cucumber), Antedon (Feather star). 40.

Protochordata (Proto—first, chordata—notochord): • They are exclusively marine, triploblastic and coelom ate. • Bilateral symmetry is found. • A long rod-like support structure called notochord is present at some stage of life. This structure runs along the back of the animal which separates the nervous tissue from the gut. Examples: Balanoglossus,Herdmania and Amphioxus.

41.

Vertebrata: • This presents the most advanced group of animals. • These animals have a true vertebral column and internal skeleton. • Vertebrates are bilaterally symmetrical, segmented with complex differentiation of body tissues and organs. • All chordates possess the following features : (i) They have a notochord. (ii) They have a dorsal nerve cord. (iii) They are triploblastic. (iv) They have paired gill pouches. (v) They are coelomate. • Vertebrates are grouped into five classes: Pisces, Amphibia, Reptilia, Aves and Mammalia.

42.

Class Pisces:

• These are fishes and exclusively water living animals. • The body is covered with scales/plates. • Body is streamlined. • Fins are present but limbs are absent. • Muscular tail is present which is used for movement. • Respiration is through gills. • They are cold-blooded and their heart are two-chambered. • They lay eggs. • Fishes are of two types based on the nature of their skeleton : (i) Cartilaginous fish—Some with the skeleton made entirely of cartilage, such as sharks, rays, etc. (ii) Bony fish—Some with the skeleton made of bones, such as Labeo rohita (Rohu), Catla, Hilsa, Anabas (Climbing perch), Exocoetus (Flying fish), Sea horse, etc. 43.

Class Amphibia (Amphi—both, bios—life): • The amphibians are the first land vertebrates, but they are found both in water and land. • They have mucus glands in the skin without scales. • Respiration is either through gills or lungs. • Heart is three-chambered, • They lay eggs. • Head and trunk distinct, neck and tail may or may not be present. • Limbs tetrapodus (four-limbed), pentadactyl type (five-fingered). Examples: Frogs, Toads and Salamanders.

44.

Class Reptilia (Creeping vertebrates): • These are first terrestrial animals living in warmer regions. • They are cold-blooded animals. • Body is divisible into head, neck and trunk. Tail is well developed in some, while it is reduced in others. • Two pairs of pentadactyl limbs are present, but in snakes limbs are reduced or absent. • Body is covered with epidermal horny scales. • Respiration takes place by lungs only. • Most of them have three-chambered heart, while crocodiles have four heart chambers. • They lay eggs with thick coverings on land. Examples; Snakes, lizards, turtles and crocodiles.

45.

Class Aves (Birds): • They are warm-blooded animals. • Heart is four-chambered. • They lay eggs. • Body is covered with a feathery endoskeleton.

• The body is divisible into head, neck, trunk and tail. • The two forelimbs are modified into wings for flight. • The breathe through lungs. • Endoskeleton is light with the bones having air cavities. • Jaws are modified to form a strong beak. Examples : Ostrich, Pigeon, Sparrow, Crow, Duck, Owl, Peacock, Parrot, etc. 46.

Class Mammalia (Mammals): • They are found in diverse habitats ranging from deserts, polar ice caps, oceans, mountains, forests and grasslands. • They are warm-blooded animals. • Heart is four-chambered. • They have mammary glands for the production of milk to nourish their young ones. • The skin of mammals has hair as well as sweat and oil glands. • They give birth to living young ones and are called viviparous, except sOme like platypus and echidna lay eggs and some like kangaroos give birth to very poorly developed young ones. • They have two pairs of pentadactyl limbs. • Eyes are provided with movable lids. Ears are fleshy external ears or pinnae. • Two sets of teeth—milk teeth and permanent teeth develop in the life time of a mammal. Teeth are of different types, i.e., heterodont. • Respiration occurs by lungs. Examples: Humans, Whale, Rat, Cat, Bat, Monkey, Elephant, Tiger, etc.

47.

Nomenclature: It is a system of giving scientific names to plants and animals. Since the name of every organism is composed of two components—genus (generic) and species (specific), so this kind of naming is termed as Binomial Nomenclature. For example, the scientific name of human species is Homo sapiens where Homo is a generic name and sapiens a specific name. Binomial nomenclature is, therefore, guided by a set of rules stated in the International Code of Binomial Nomenclature. Binomial Nomenclature was proposed by Carolus Linnaeus.

48.

Scientific names : The names given to living organisms following the binomial system are called scientific names. Scientific names of some common organisms are as follows : Common name Pea Mango Tiger Peacock

Scientific name Pisum sativum Mangifera indica Panthera tigris Pavo cristatus

Certain conventions are followed while writing the scientific names: (i) The name of the genus begins with a capital letter.

(ii) The name of the species begins with a small letter. (iii) When printed, the scientific name is given in italics, (iv) When written by hand, the genus and the species names have to be underlined separately. 49.

Comparison of Thallophyta, Bryophyta and Pteridophyta : Thallophyta

Bryophyta

Pteridophyta

Plant body thallus-like, not differentiated into root, stem and leaves.

Plant body does not have true roots, stems and leaves but shows rootlike and leaf-like structures. True vascular system is absent. Multicellular sex organs. Embryo is formed after fertilsation. It includes mosses and liverworts.

Plants have true roots, stems and leaves.

No vascular system. Single-celled sex organs. No embryo formation after fertilisation. It includes algae. 60.

Differences between: Gymnosperms

Vascular system is present. Multicellular sex organs. Embryo is formed after It includes ferns.

Angiosperms

(i) The seeds are naked. (i) The seeds are enclosed by fruit wall. (ii) The microspores and megaspores are (ii) The microspores are produced in produced by male and female cones. anthers while the megaspores are produced in ovules of the ovary in flowers. (iii) Xylem lacks vessels and phloem (iii) Xylem contains vessels and phloem lacks companion cells. also contains companion cells.. (iv) The ovules are not located in the (iv) The ovules are enclosed in the ovary. ovary. 51.

Bilateral Symmetry: Body organisation in which one median plane can divide an organism into left and right halves, each a mirror image of the other.

52.

Radial Symmetry: Arrangement of similar parts around a central body axis as in a wheel or column.

53.

Cold-blooded (Ectothermy) : The condition in which the internal temperature of an animal is dependent upon the temperature of its environment.

54.

Warm-blooded (Endothermy): The condition in which the internal temperature of an animal is dependent upon its metabolic processes and is held at a relatively high and constant level.

55.

Diploblastic : Animals having a body made of two germ or embryonic layers of cellsectoderm and endoderm.

56.

Triploblastic : Animals having a body made of three germ layers—ectoderm, mesoderm and endoderm. Endoskeleton : Bony and cartilaginous supporting structures within the animal body which provides support from within.

57. 58.

Pseudocoelom (False coelom): The body cavity lined on one side by ectoderm and the other side by endoderm.

59.

Exoskeleton: Calcareous, chitinous or other hard material covering the body surface and providing protection or support.

60.

Hermaphrodite: An individual who possesses both female and male reproductive organs.

61.

Metamerism: The division of the body into a linear series of similar parts of segments, as in Annelids and Chordates.

62.

Notochord : A flexible rod of turgid cells located along the back of chordate embryos, ventral to the nerve cord. It acts as a support and usually replaced by the ventral column in adult vertebrates.

63.

Water Vascular System : A unique system of radiating canals in echinodermates used for locomotion, excretion and circulation.

64.

Vertebral Column : A flexible bony column in vertebrates that extends down the long axis of the body and provides the main skeletal supports. VERY SHORT ANSWER-TYPE QUESTIONS (1 MARK)

1.

In which kingdom will you place an organism which is single-celled, eukaryotic and photosynthetic ? [NCERT]

2.

Which division among plants has the simplest organisms ?

3.

What is classification ?

4.

What is taxonomy ?

5.

What is species ?

6.

What is nomenclature ?

[NCERT]

7.

What is the scientific name of humans ?

8.

Who proposed the binomial nomenclature of classification and is considered as 'Father of Taxonomy' ? What was his nationality ?

9.

What is the role of "International Code of Binomial Nomenclature" ?

10.

Name the group in which related genera are placed.

11.

Name the group in which : (i) Seeds are naked, (ii) Reproductive organs are flowers.

12.

How many chambers are present in the heart of (i) fishes (ii) frog ?

13.

Name the basic unit of classification.

14.

What is the first act of taxonomy ?

15.

Name the smallest taxon.

16.

Name two sub-kingdoms of Kingdom Plantae.

17.

What are phanerogams ?

18.

Give one point of difference between Gymnosperms and Angiosperms.

19.

Name a group where naked seeds are present.

20.

To which division of Cryptogams do algae belong ?

21.

To which phylum do sponges belong?

22.

Which is the largest phylum of Kingdom Animalia ?

23.

The animals belonging to a phylum have segmented body. Name the phylum.

24.

Name two mammals living in water.

25.

Name two animals belonging to reptilian class.

26.

Write one specific feature of thallophyta plant.

27.

To which phylum do earthworm and leech belong ?

28.

What is the most important feature of Arthropoda ?

29.

Which organisms are included in Arthropods ?

30.

Which type of animals are included in Mollusca ?

31.

Why is octopus so called ?

32.

From where do the term echinoderms originate ?

33.

Why are mammals so called ?

34.

Name one aquatic mammal and one egg-laying mammal.

35.

Give the technical term of naming animals and plants with two words, i.e., one generic and other specific.

36.

Name the seven basic hierarchial categories.

37.

Name the host of tapeworm.

38.

Name the limbless vertebrate.

39.

In which groups are diploblastic animals found ?

40.

What is lichen ?

41.

Define pseudocoel.

42.

What is tube-within-a tube plan ?

43.

What was the basis of five kingdom classification proposed by Robert Whittaker ?

44.

Which organisms are included in Kingdom Protista ?

45.

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

46.

Which division of plants is called the amphibians of the plant kingdom ?

47.

Which are the smallest and the largest bird ?

48.

Mention an organism which exhibits characters of both plants and animals.

49.

How are oviparous and viviparous animals different from each other ?

50.

Why is Euglena called plant-animal ?

51.

Give two peculiar characters of sponges.

52.

Give the habitat and economic importance of Taenia solium.

53.

What is metameric segmentation ? In which group of animals is it reported ?

54.

What is haemocoel ? Which groups of animals have haemocoel ?

55.

How does a male cockroach differ from a female cockroach ?

56.

In what way, are amphibians advanced than the fishes ?

57.

Why are bats not placed in birds ? Differentiate them.

58.

Why are frogs not seen in the winter months ?

59.

List two differences between lizards and snakes.

60.

Give one difference between cartilaginous and bony fishes.

61.

Name three flightless birds.

62.

Give one example of each : (i) asymmetry, radial and bilateral symmetry. (ii) acoelomates, pseudocoelomate and haemocoelomate. (iii) diploblastic and triploblastic animals.

63.

Name a fresh water sponge and a coelenterate.

64.

Name the phylum in which animals have tissue level organisation.

65.

Name the phylum to which the following belong : (i) Silver fish (ii) Sea horse (iii) Sea cucumber (v) Devil fish (vi) Star fish (vii) Crayfish

(iv) Jelly fish

66.

Identify the animal group having: (i) Body spiny and radial symmetry. (ii) Bones light and hollow. (iii) Soft-bodied animals supported by calcareous shells. (iv) Four pairs of jointed legs, head and thorax fused.

67.

Give the scientific names of the following: (i) Liver fluke (ii) Tape worm (iii) Cattle leech (v) Housefly (vi) Starfish (vii) Indian Shark (ix) Frog (x) Flying Lizard

68.

Which phylum have the following characteristics ? (i) Plants without tissues, body bearing pores.

(iv) Cockroach (viii) Climbing Perch

(ii) Unsegmented soft-bodied having a calcareous shell, ventral foot and mantle. (iii) Body segmented, jointed legs, compound eyes. 69.

Which is the largest phylum of animal kingdom ?

[NCT2003, KVS 2006]

70.

Name the phylum in which the animals have water vascular system.

[DAV2003,2006]

SHORT ANSWER-TYPE QUESTIONS (2 MARKS) 1.

What do you think is a more basic characteristic for classifying organisms ? (i) The place where they live. (ii) The kind of cells they are made of Why ? [NCERT]

2.

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

3.

Which organisms are called primitive and how are they different from the so-called advanced organisms ? [NCERT]

4.

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

5.

What is the criterion for classification of organisms as belonging to Kingdom Monera or Protista ? [NCERT]

6.

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 ? [NCERT]

7.

How are pteridophytes different from the phanerogams ?

8.

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

9.

Explain the basis for grouping organisms into five kingdoms.

10.

What are the criteria for deciding divisions in plants different from the criteria for deciding the sub-groups among animals ? [NCERT]

11.

Why are whales not grouped in the fishes ?

12.

Give two structural adaptations in the birds for flight.

13.

Why are the primates more intelligent than other mammals ?

14.

Differentiate between radial and bilateral symmetry.

15.

What are the advantages in the scientific names ?

[NCERT]

[NCERT]

[NCERT]

16.

How did Carolus Linnaeus divide the living organisms ?

17.

What kind of organisms are included in plant kingdom ?

18.

How is the plant kingdom sub-divided further ?

19.

Name the group of plants that belongs to the division Thallophyta.

20.

On what basis are the animals divided or classified ?

21.

Give one point of difference between notochord and nerve cord.

22.

How are the seed-bearing plants further classified ?

23.

What is the need of nomenclature ?

24.

What are Algae ?

25.

What are Fungi ?

26.

What are Bryophyta ?

27.

What is the basis of classification for Gymnosperms and Angiosperms ?

28.

What are Coelenterates ? Mention some examples.

29.

Which types of organisms are included in Platyhelminthes and why are they named so ?

30.

Draw a flow-diagram to show the five kingdom classification.

31.

What is the basis of classification for Gymnosperms and Angiosperms ?

32.

Which type of organisms are included in Platyhelminthes and why are they named so ?

33.

Give the main differences between Bryophyta and Pteridophyta.

34.

Write the convention followed while writing the scientific names.

35.

What is Binomial Nomenclature ? Explain it with the help of an example.

36.

Differentiate between Taxonomy and Systematics.

37.

Give some examples of mammals with their scientific names.

38.

Give the importance of taxonomy.

39.

Give two important characters of bony fishes.

40.

Give one [KVS2003]

41.

What are the four main characteristics of chordates ?

point

of

difference

between

Gymnosperms

and

Angiosperms.

[KVS 2004; NCT 2006]

SHORT ANSWER-TYPE QUESTIONS (3 MARKS) 1.

Why do we classify organisms ?

2.

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

3.

On what basis are plants and animals put into different categories ?

4.

How do [NCERT]

5.

How do poriferan animals differ from coelenterate animals ?

6.

How do annelid animals differ from arthropods ?

[NCERT]

7.

What are the differences between amphibians and reptiles ?

[NCERT]

8.

What are the differences between animals belonging to the aves group and those in the mammalia group ? [NCERT]

9.

What are the advantages of classifying organisms ?

10.

What are the major divisions of the plantae ? What is the basis for these divisions ? [NCERT]

11.

Draw diagram of a Gymnosperm and an Angiosperxn.

12.

Give some characteristic features of animals.

13.

How does classification of organisms help us ?

14.

Differentiate between a plant and an animal.

15.

Describe the characteristics of the division Thallophyta.

16.

Describe the characteristics of the division Bryophyta.

17.

Describe the characteristics of the division Pteridophyta.

Gymnosperms

and

[NCERT]

Angiosperms

differ

from

each

other

?

[NCERT]

[NCERT]

18.

How are Phanerogamae divided into sub-divisions ?

19.

Why are local names not sufficient to recognise the organisms ? What are the advantages of keeping scientific names ?

20.

List some adaptation of reptiles towards terrestrial mode of life.

21.

List a few flight adaptations in birds.

22.

Draw labelled diagram of few Protozoans.

23.

Draw the phylogenetic tree to show the natural relationship among various animal phyla.

24.

Give one point of difference between : (i) Bony and cartilaginous fish. (ii) Bilateral and radial symmetry. (iii) Notochord and nerve cord.

[NCT 2004; KVS 2006] [NCT2004] [NCT2004]

25.

State three points of differences between cartilaginous fish and bony fish. [DAV2004]

26.

Why are local names not sufficient to recognise the organisms ? What is binomial nomenclature ? Explain it in brief giving an example. [NCT 2005]

27.

Name the phylum to which each of the following animals belong to : Sea horse, Silver fish, Starfish, Sycon, Tapeworm, Leech, Amoeba, Hydra. [KVS2005] LONG ANSWER-TYPE QUESTIONS (5 MARKS)

1.

Explain how animals in Vertebrata are classified into further sub-groups.

2.

Write the characteristics of phylum Porifera.

3.

Write the characteristics of phylum Coelenterata.

4.

Write the characteristic features of phylum Platyhelminthes.

5.

Write the characteristic features of phylum Nematoda.

6.

Write the characteristic features of phylum Annelida.

7.

Write the characteristic features of phylum Arthropoda.

8.

Write the characteristic features of phylum Mollusca.

9.

Write the characteristics of class Echinodermata.

\PICERT]

10.

Write the characteristic features of Kingdom Monera.

11.

Write the characteristic features of Kingdom Protista.

12.

With the help of diagram, give the difference between dicotyledons and monocotyledons.

13.

Give the comparative summary of the vertebrate classes.

14.

Give five kingdoms of life in a tabular form mentioning their features with examples.

15.

(i) What ate the four main characteristics of chordates ? (ii) Differentiate between (one differences only) (a) Vertebrates and Invertebrates. (b) Chondrichthyes and Osteichthyes. (c) Reptiles and Mammals;

[KVS 2003]

SELF EVALUATION TEST [Time Allowed : 1 hour]

[Max. Marks : 25]

1.

Who proposed the binomial system of nomenclature ?

1

2.

Name the reproductive organs of gymnosperms and angiosperms.

1

3.

How are pteridophytes different from phanerogams ?

2

4.

Give the scientific name of the following : (i) Round worm (ii) Filarial worm.

2

5.

Define the term hermaphrodite. Give two examples.

2

6.

What are the adaptations in fishes due to which they are aquatic ?

3

7.

Distinguish between— (i) Annelida and Arthropoda (ii) Aves and Mammals (iii) Amphibia and Reptilia

3

8.

Give four characteristics of mammals. Give two examples.

3

9.

What are pisces ? Classify and explain them with suitable examples.

3

10.

Name the major phyla of animals, alongwith one or two main features and examples.

5