CHAPTER 4 ~ ANIMAL KINGDOM CONCEPT MAP Animal kingdom Invertebrates Vertebrates (WNos-shordatay (Chordata) ‘Celta level Tissue loved ‘Organ and 1 Phy Porters _2Pryium Cnidaria ‘organ system Tove! Acoelomata Coolomata (No body cavity) (Body cavity present) 3. Phylum Patyelmintes 5. Phylum Annelida 44 Phyim Nematoda 6, Phylum Arthropoda 7. Phylum Musca 8. Phylum Ectinodermata (Class Pisces (i) Class Amphibia (i) Class Reptta. (iv) Class Aves (v) Class Mammal POINTS TO REMEMBER Animals ate muiicellular and heterotrophic organisms without cell wall and chlorophyll, Kingdom ‘Animalia Inckades 11 major phyta: 1) Poriéera 2)Critaria 3)Ctenophora 4)Pluyhelminthes 5)Aschelminthes 6) Anmelida 7) Anbropoda 8)Molksca 9)Echinodermata 10)Hemichordata 11) Chordata 1, LEVELS OF ORGANIZATION Based on this, animals are grouped into four level a. Cellular level of organization: Here, the cells are arranged as loose cell ageregates. Eg. Poriera. bb, Tissue evel of organization: Here, the cells are arranged into tissues. E.g. Cnidarians. and Ctenophores, cc. Organ level of organization: Here, tissues are arranged info organs. E.g. Higher animals (Pliyhelminthes to chordates). 4. Organ system Jevel of organization: Here, organs are associated to form organ system. Each system performs a specific physiological function. Eg. Aschelminthes to chordate Organ systems of various animals show compkxities. Eg, Higher Animals 2 CIRCULATORY SYSTEM is 2 types: open & closed. 3. BODY SYMMETRYIts the arrangement of similar body parts on 2 sides of main axis of the body. Based on symmetry, animals are 2 types: Asymmetrical and Symmetrical. Asymmetrical: Here, body cannot be divided into 2 equal halves. E.g. Most members of porifera, Symmetrical: Here, body can be divided into 2 equal halves. It is 2 types. + Radial symmetry: Here, body can be divided into 2 equal halves in any vertical plane along central axis (oral-aboral axis) of the body. E.g. Members of Cnidaria, Ctenophores and Echinoderms (adult) Bilateral symmetry: Here, body can be divided into right & left halves in only one plane. Eg. Pkiyhelminthes to Chordata (except adult Echinodermata) 4, Germinal ayers (Embryonic layers) ‘These are layers of embryo from which all the body organs are formed. Based on the number of germ lhyers, animals are 2 types- Diploblastic and Triploblastic. ‘a. Diploblastic animals: 2 germ layers- outer ectoderm and inner endoderm. In between these layers, an ‘undifferentiated jelly-like layer called mesoglea is present. Fg, Cnidaria & Ctenophora. 1b Triploblastic: animals: 3 germ layers- Outer ectoderm, middle mesoderm and inner endoderm E.g. latyhelminthes to Chordata. 5. Coelom (body cavity‘ is the cavity lined by mesoderm It is seen between body wall and gut wall. ‘Coclom separates the muscles of gut and body wall Based on the nature of coelom, animals are 3 types: a. Acoelomate: Nocoelom. The space between body wall and digestive cavity is filed with matrix (parenchyma). E.g. Porifera to Platyhelminthes, b. Pseudocoelomute: False coelom. Here, the body cavity is not lined by mesoderm Mesoderm is scattered pouches. F.g. Aschelminthes.Coelomate _Pseudocaelomate _Acoelomate ¢. Coclomate: True coelom Here, the coelom arises from the mesoderm Coelom is lined by peritoneal layer and filled with coelomic fd, Eg. Annelida to Chordata, Funetions of coelom: + Ttaccommodates visceral organs.Coelomic fluid reduces friction between visceral organsIt acts as shock absorber. 6. Metamerisin (segmentation Itis the phenomenon in which the body or organs is externally and intemally divided into repeated segments (metameres). Eg, Annelids (earthworm etc,), Arthropods. Notochord Iisa mesodermally derived supporting rod formed on the dorsal side during embryonic development in some animals. Animals with notochord are called chordates and those without notochord are called non- cchordates. Phylum Porifera (Sponges): General Characters Grades of organization:Cellutur grade. ‘Symmetry:Asymmetrical. Some are radial CoclomAcoelomate Habit and habitatAquatic (mostly marine), Sedentary. Solitaryicolonia. Digestive systemcAbsent, Intracellular digestion, Respiratory system:Absent Circulatory systenrAbsent Reproduction:Asexual (fragmentation) & Sexual Hermaphrodite (Monoecious): Male and female sex organs are seen in same individual + Internal fertilization Development is inet. 10. Unique features: + Water canal (water transport) system Millions of ostia (pores), + Water canal system Here, water enters through minute potes (ostia) in the body wall into central cavity (spongocoe), from where it goes out through osculum. Canal system is wed for food gathering, gas exchange and removal of wastes. + Spongocoe! & canals are tined with choanocytes (collar cells) + Body is supported by spicules and spongin fibres. 11. Examples: + Sycon (Seypha), Spongilta (fresh water sponge), Euspongia (Bath sponge) + Phylum Cnidaria (Coelenterata): General Characterseen aweene Grades of organization:Tissue grade, Symmetry:Radial symmetry. Germ hyers:Diploblastic CoeloneAcoelomate Habit and habitat: Aquatic (mostly murine) Sessile/free swimming. Solitary/colonial Digestive systenrlncomplete.Intracellular & extracellular digestion Respiratory systemAbsent Circulatory system:Absent Reproduction: Polyp reproduces asexually (budding) and medusa sexually. ‘Most are separate sexes.,Extemal fertilization Development is indirect. Unique features:Tentacles with cnidoblasts. Tenlacks: Finger-like structures which surrounds the mouth of coelenterates. Used for food capture & defense. Cridoblasts (Cridocytes): These are stinging cells (present on the tentack’s and the body) with a poison-filled capsule called nematocyst. Cnidoblast is used for anchorage, Thread — } Nematocyst Cnidoblast defense and to capture prey. Gastro-vascular cavity (coelenteron) with an opening (mouth) on hypostome, Polyp & Medusa: 2 types of body forms in cnidarians. Polyp is tubular attached asexual form, with upwardly directed mouth & tentacks, Eg. Hydra, Adamsia ay ‘Medusa is umbrella like, free-swimming sexual form, with downwardly directed mouth & tentacks, E.g. Aurelia (Jelly fish).Some shows akemation of generation. ‘Alteration of generation (Metagenesis): The phenomenon in which polyps produce medusae asexually and medusae form the polyps sexually. Eg Obelia. Corals have skeleton (CaCO3). Exampks Hydra, Obelia, Aurelia, Physalia (Portuguese man of wat), Adamsia (Sea- anemone), Pennatula (Sea pen), Gorgonia (Sea fan), Meandrina (Brain coral). Grades of organization: Tissue grade. Symmetry: Radial symmetry.Germ hyers:Diploblastic Coelom:Acoelomate Habit and habitatExclusively marine Solitary & pelagic Digestive systemIncomplete. Intracellular & extracellular digestion. Respiratory systemAbsent Circuluory_systemrAbsent Reproduction:Only Sexual, Hermaphrodite.,External fertilization, Development is indirect. Unique features: + Locomntion is by 8 vertical extemal rows of ciliated comb pltes.,Tentackss present. + Shows Bioluminescence (property to emit light from the body). Examples:Ctenoplana, Pleurobrachia, 10. Grades of organization-Organ & Organ system. Symmetry ‘Bilateral. symmetry. Germ kyers:Tripbblastic. Coelom:Acoelomate Habit and habitatMainly aquatic. Endoparasites.Some are free-living. Digestive systemIncomplete. Respiratory systemAbsent Circultory_systenrAbsent Reproduction:Asexual (fragmentation) and Sexual + Hermaphodite.Internal Fertilization. “+ Development is indirect Many larval stages. ‘Unique features: “+ Uncegmented, dorso-ventrally flattened body (except tape worms). + Excretion and osmo-regulation by Flame cells (protonephridia). + Parasites have Hooks & suckers. ‘Some absorb nutrients from the host through their body surface. Exampes: Taenia solium (Tape worm), Fasciola (Liver fluke), Planaria (shows high regeneration capacity). Poyum ‘Aschelminthes (Roundworms): General Characters 10. Grades of organization-Organ system. Symmetry:Bilateral symmetry. Germ hyers:Triploblastic. CoelomPseudocoelomate. Habit and habitat Aquatic and terrestrial, Free living or parasitic in plants & animals, Digestive systemComplete, Tubular alimentary canal with well-developed muscular pharynx, Respiratory systemAbsent Circulatory. system-Absent Reproduction: = Dioecious (Sexes are separate).Sexual reproduction. ‘Internal fertilization. Development is direct or indirect. Unique features:Body is circular in cross section.* Syncytial epidermis. Thick cuticle. + An excretory tube to remove body waste through excretory pore, * Sexual dimorphism (Morphological differences between male and femme. Eg. females are longer than males). 11, Examples: © Ascaris (Roundworm), Ancylostoma (Hookworm), Wuchereria (Fiarial worm) Phykim Annelida (Segmented / Ringed Worms): General Character 1. Grades of organizationOrgan system. Symmetry:Bilateral. symmetry. Germ layers:Triploblastic, ‘Coelom:Coelomate, Habit and habita:Terrestrial, fresh water or marine. Free living or parasitic. Digestive systemComplete. Respiratory systemCutaneous respiration, Some have branchial (gill) respiration. Circulatory systemClosed type. Reproduction:Sexual + Earthworms & leeches are monoecious.Neties is dioecious Development is direct or indirect. 10. Unique features: + Segmentation like rings.Longitudinal and circular muscles help in locomotion. + Locomptory organs are setae (in earthworm) or parapodia (in Neti). + Excretion by Nephridia Paired ganglia connected by lateral nerves to a double ventral nerve cord. 11, Exampks: *+Pheretima (earthworm), Hirudinaria (blood sucking Leech), Neries (aquatic. Parapodia for swimming). Sen away Phylum Arthropoda (Joint-Legged Animals): General Characters Arthropoda is the largest phylum. Over two-thirds of all named species are arthropods. Grades of organizationOrgan system. SymmetryBilateral_ symmetry. Germ kayers:Triploblastic. Coelom:Coelomate, Habit and habitatCosmopolitan. Digestive systemComplete. Respiratory system: * Gill book gils/ trachea/book hungs. Circulatory systemrOpen type. Reproduction: Mostly dioecious. * Usually internal fertilization oviparous.Development is direct or indirect. 10, Unique features + Jointed appendages. Body has 3 regions: head, thorax & abdomen. + Body is covered by chitinous cuticle (exoskeleton).Excretion by Malpighian tubules. + Sensory organs are antennae, compound & simple eyes, statocysts (bakince organs). 11, Examples: Navewne rd+ Spider, Scorpion, Crab, Prawn, Insects etc, + Economically important insects: Apis, Bombyx, Laccifer. + Vectors: Mosquitoes (Anopheles, Culex & Aedes), Housefly et. + Gregarious_pest; Locusta. + Living_fossil; Limulus (King ctab). Phykim Mollusca (Soft Bodied Animal): General Characters ‘Molusca is the second largest phylum. 1. Grades of organizationOrgan.systemSymmetry:Bilateral symmetry. Germ yers:Triploblastic, Coelomate, Habit and habitat:Aquatic.Few are terrestriaLDigestive systemComplete. Respiratory systemGills in aq. forms and pulmonary sac in terrestrial forms. Circulatory systemOpen type. Reproduction: Dioecious.O viparous. Development is direct or indirect. Unique features:Body has head, visceral mass (visceral hump) & muscular foot. Head has sensory tentacks.Caicareous sbell.Feather-like gill) for respiration & excretion, + Mantle & radula are seen.Mantle (Pallium): The membrane which covers visceral mass. Space between the hump and mantle is called mantle cavity. sayeen ‘*Radula: File-lke rasping organ present in the mouth of molluscs. It is used for feeding, ‘*Exampkes: Pila (Apple Snail), Pinctada (Pearl Oyster), Sepia (Cuttlefish), Loligo (Squid), Octopus (Devil fish), Aplysia (Sea Hate), Dentatium (Tusk shell), Chaetopleura (Chiton), Phylum Echinodermata (Spiny Skinned Animals): General Characters a. Grades of organization Organ system. a. Symmetry:Adults radial Larvae bilateral, Germ kayers:Tripioblastic. CoelomCoelomate.Habit and habitat:Exclusively marine, Digestive systemComplete, Ventral mouth and dorsal anus. Respiratory systemDermal branchiae (skin gils or papulae) and tube feet Circulatory systemOpen type. Repredction Dioecious. External fertilization, Development is indirect.Ciliated_ free-swimming a Unique features:They have an endoskeleton of calcareous ossicles (Spiny bodied).Head absent. © Water vascular system present © Water vascular (ambulicral) system: In this system, sea water enters through a porous plate called madreporite and reaches the radiating canals and tube feet (podia). Its functions are locomotion, respiration, capture & transport of food and excretion, «© Excretory system absent.Shows autotomy & regeneration, Examples: Asterias (Starfish), Echinus (Sea Urchin), Echinocardium, Antedon (Sea Lily), Cucumaria (Sea Cucumber), Ophiuira (Britt Star). aes Fens Phylum Hemichordata; General Characters Hemichordata was earlier considered as a sub-phykim of Chordata. Like chordates, it has pharyngeal gill slits, a. Grades of organization:Organ system Symmetry:Bilateral,Germ layers:Triploblastic. ». CoelomCoelomate, Habit and habitat:Exclusively marine©. Digestive systemComplete.Respiratory system:Gill.Circulatory systemOpen type. 4. Reproduction:Dioecious.External_ fertilization Development is indirect. Unique features:Worn like cylindrical body formed of anterior proboscis, a collar and a long trunk.Collar bears stomochord (a rudimentary structure similar to notochord).Excretion by Proboscis gland Examples: Balanoglossus (Tongue worm), Saccoglossus. Phylum Chordata 1. Itincludes animals with notochord, dorsal tubular nerve cord and pharyngeal gill sits. Nerve cord Notochord Post-a Sill slits re Chordata characte: (Body plan) 2. Notochord is a flexible rod located in the mid dorsal fine between the alimentary canal and the nerve cord in the embryo, Differences between Chordata and Non-Chordata Chordata, Non-Chordata 1. Notochord is found in the embryonic. sage Absent 2 Central nervous system & dorsal, hol an singe Ventral, solid and double 3. Pharyngeal gil sits present ‘Absent 4. Ventral heart Dorsal heart (if present) 5. Apost-anal part (ai) 8 present | anoony Phykim Chordata is classified into 3 subphyl: Urochordata, Cephalochordata & Vertebrata. PROTOCHORDATA (ACRANIATA) Urochordata (Tunicata) ‘Cephalochordata ~ Notochord present only in the larval tail ‘Notochord from head to tail region and is Body is covered persistent throughout fie. by atest made up of tunicin, Fish-fke body. Exchsively marine. Exchsively marine + Hermaphrodite. + Sexes are separate, + Eg. Ascidia, Salpa, Doliolum + Eg. Branchiostoma (Amphioxus or Lancet).ie Possess notochord during the embryonic period. Notochord is replaced by a cartiaginous or bony vertebral column in the adult Veniral mascular heart Kidneys for excretion & osmoregulation Paired appendages (fins or limbs). yeep Chissifcation Of Vertebrata Chss Cyclostomnta All are ectoparasites on some fishes.Elongated body without scales and paired fins. (6-15 pairs of gil sits for respiration. Sucking and circular mouth without jaws. Cartiaginous cranium and vertebral column Circulation is a closed type. ‘Marine, but migrate for spawning to fresh water. Afier spawning, they dic, Their lnrvae, after metamorphosis, retum to the ocean.E.g. Petromyzon (Lamprey) and Myxine (Hagfish), 'SUPERCLASS PISCES (FISHES) Class Chondricthyes (Cantilaginous fishes) ‘Marine, Streamlined body. Predaccous.Cartiaginous endoskeleton, Notochord is persistent throughout li. Ventral mouth.Gill slits without operculum. Powerful jaws. ‘Skin with placoid scales, Teeth are modified plicoid scales which are backwardly directed, No air bladder. So, they have to swim constantly to avoid sinking Poikilotherms (coK1-blooded). ‘Two-chambered beart (one auricle and one ventricle) Sexes are separate. In mules, pelvic fins bear cclaspers, Internal fertilization, Many of them viviparous. Examples: Scoliodon (Dogfish), Pristis (Saw fish), Carcharodon (Great white shark), Trygon (Sting ray- has poison sting), Torpedo (Electric ray- has electric organ). Class Osteichthyes (Bony fishes) Marine & fresh water, Streamlined body.Bony endoskeleton-Terminal mouth pairs of gills covered by operculum on each side. Scales are Cyclo, ctenoid ete Air bladder for buoyancy. Poikilotherms (cokl-blooded).Two-chambered heart (one auricke and one ventricle). ‘Sexes are separate. External fertilization Mostly oviparous. Development is direct. Examples:Marine: Exocoetus (lying fish), Hippocampus (seahorse) Fresh water: Labeo (Rob), Catla (Kath), Clarias (Magur). Aquarium: Berta Fighting fish), Prerophyllum (Angel fish). SUPERCLASS TETRAPODA. Cass Amphibia ‘They live in aquatic & terrestrial habitats and need water for breeding. Body has head & trunk. Some have tail Moist skin without scales. Most have 2 pairs of limbs. ‘Tympanum represents ear.3-chambered beart (2 aurick + 1 ventricle), Poikilotherms Alimentary canal, urinary & reproductive tracts open into a Cloaca which opens to exterior. Respiration is by gills (in larva), lungs & skin Sexes are separate. External fertilisation. Oviparous.Development is indirect, Exampks: Bufo (Toad), Rana (Frog), Hyla (Treetrog), Salamandra (Salamander), Ichthyophis (Limbless amphibia), Class Reptilia Dry & comified skin, epidermal scales or scutes.Snakes and lizards shed their scales as skin cast. Limbs- 2 pairs (if present) Crawling mode of locomotion. 7ympanum represents eat. 3-chambered beart (but a septum partially separates ventricle). Heart is 4- chambered in crocodiles. PoikilothermsWell-developed alimentary canal. Respiration by dungs.Intemal fertilisation. Oviparous.Development is direct. Examples: Chelone (Turtle), Testudo (Tortoise), Chameleon (Tree lizard), Calotes Garden lizard), Crocodilus (Crocodik), Alligator, Hemidactylus (Wall lizard). Poisonous snakes: Naja (Cobra), Bangarus (Krait), Vipera (Viper) ete. Non-poisonous snakes: Python etc. Chass Aves (Birds) Presence of feathers and beak. Forelimbs. are modified imo wings. Dry skin without glands except the oil gland at the base of tail Hind limbs have scales and are modified for walking, swimming or clsping tree branches. Hollbw & pneumatic long bones.7ympanum represents ear.4-chambered heart. HomoiothermsDigestive tract has additional chambers, the crop & gizzard. Double respiration Air sacs connected to hngs...nternal fertilisation. Oviparous.Development is direct. Exampks: Corvus (Crow), Columba (Pigeon), Psittacula (Parrot), Struthio (Ostrich), Pavo (Peacock), Aptenod ytes (Penguin), Neophron (Vuure) etc.Class Mammalia * Presence of mammary glinds (milk producing glands), © Skin with hair.2 pairs of limbs for walking, running, climbing, burrowing, swimming or © External ear (Pinnae).4-chambered heart. HomoiothermsWell-developed alimentary canal © Denton is Heterodont, thecodont & diphyodont Respiration by hings.Sexes are separate © Internal fertilisation. Viviparous (except Echidna and Platypus).Development is direct. Exanpks: Omithorhynchus (Platypus), Macropus (Kangaroo), Preropus (fying fox), Camelus (Camel) ‘Macaca (Monkey), Rattus (Rat), Canis (dog), Felis (Cat), Elephas (Elephant), Equus ( Horse), Delphinus (Common dolphin, Balaenoptera (blue whale), Panthera tigris (Tiger), Panthera leo (hon). + Poikilotherms (Cold-blooded animals): Animals that lack the capacity to regulate their body temperature + Hompiotherms (warm-blooded animals); Animals having abiity to maintain a constant body temperature QUESTION AND ANSWER Question 1: What are the difficulties that you would face in chssification of animals, if common fundamental features. are not taken into account? ANSWER: For the classification of living organisms, common fundamental characteristics are considered, If' we consider specific characteristics, then each organism will be placed in a separate group and the entire objective of classification woukl not be achieved. Classification of animals is ako important in comparing different organisms and judging their individual evolutionary significance. If only a single characteristic is considered, then this objective would not be achieved, Quest 2: Ifyou are given a specimen, what are the steps that you woukl follow to classify it? ANSWER: There is a certain common fundamental feature that helps in classification of be features that can be used in chssification are as follows. On the basis of above features, we can easly classify a specimen into its respective category: Question 3: How usefil is the study of the nature of body cavity and coelom in the classification of animals? ANSWER: Coelom is a fluid filed space between the body wall and digestive tract. The presence or absence of body cavity or coelom plays a very important role in the chisification of animals. Animals that possess a fluid filled cavity between body wall and digestive tract are known as coelomates. Annelids, mollusks, arthropods, echinodermates, and chordates are examples of coelomates. On the other han, the animals in which the body cavity is not lined by mesoderm are known as pseudocoelomates. In such animals, mesoderm is scattered in between ectoderm and endoderm. Aschelminthes is an example of psetwlocoelomates. In certain animals, the body cavity is absent. They are known as acoelomutes. An example of acoelomates is platyhelminthes.Question 4: Distinguish between intracellular and extracellular digestion? ANSWER: Tntracellular_ digestion “Extracellular digestion: “The digestion of food occurs within the cet. | 1, | T® gestion occurs in the eavigy of alimentary canal, Digestive enzymes are secreted by the | | Digestive enzymes ate secreted by speci cells surrounding cytoplasm into the food vacuok. into the cavity of alimentary canal Digestive products are diused nto. the [| Digestive products diffuse across the aiestinal | cytoplasm. wall into various parts of the body. Tis a kes efficent_ method, 3, [Ttis a more effcient_ method of digestion, Troccurs i unicellular organisms 3__[Ttoccurs in muiti_celur organisms. Question 5: What is the difference between direct and indirect development? ANSWER: Direct Development Indirect Development T. | Its a ype of develbpment i which an T, | Its a type of development that involves a embryo develops into a mature individual sexually: immature larval stage, having without different involving a larval_ stage. food requirements than adults, 2 | Metamorphosis absent Z| Metamorphosis involving development of fava to a sexually-mature adult is present. 3. It occurs in thes, repties, bids, | 3. | occurs m most ofthe invertebrates and and maromals. amphibians. Question 6: What are the peculiar features that you find in parasitic pltyhelminthes? ANSWER: Taenia (Tapeworm) and Fasciola (iver fuke) are examples of parasitic platyhelminthes. Peculiar features in parasitic platybelminthes are as flows. 1. They have dorsiventrally flattened body and bear hooks and suckers to get attached inside the body of the host 2. Their body is covered with thick tegument, which protects them from the action of digestive juices of the host. 3. The tegument also belps in absorbing nutrients from the host's body Question 7: What are the reasons that you can think of for the arthropods to constitute the largest group of the animal kingdom?ANSWER: The phylum, Arthropoda, consists of more than two-thirds of the animal species on earth. The reasons for the success of arthropods are as follows. i Joimted legs that allow more mobility on land ii, Hard exoskeleton made of chitin that protects the body iii, The hard exoskeleton ako reduces water Joss from the body of arthropods making them more adapted to terrestrial conditions Question 8: Water vascular system is the characteristic of which group of the following: (a) Porifera (b) Ctenophora (c) Echinodermata (d) Chordata ANSWER: Water vascular system is a characteristic feature of the phylum, Echinodermata. It consists of an array of radiating channels, tube feet, and madreporite, The water vascular system helps in locomotion, food ‘capturing, and respiration, Question 9: “All vertebrates are chordates but all chordates are not vertebrates”. Justify the statement. ANSWER: The characteristic features of the phylum, Chordata, inclade the presence of a notochord and paired pharyngeal gill sits. In sub-phylum Vertebrata, the notochord present in embryos gets replied by a cartiginous or bony vertebral column in adults. Thus, it can be said that all vertebrates are chordates but all chordates are not vertebrates. Question 10: How important is the presence of air bladder in Pisces? ANSWER: Gas bladder or air bhdder is a gas filed sac present in fishes. It helps in maintaining buoyancy. Thus, it helps fishes to ascend or descend and stay in the water current. Question 11: What are the modifications that are observed in birds that belp them fly? ANSWER: Birds have undergone many structural adaptations to suit their aerial fe. Some of these adaptations are as follows. (9 Streamlined. body for rapid and smooth movement i) Covering of feathers for insulation (iii) Forelimbs modified into wings and hind limbs used for walking, perching, and swimmning (iv) Presence of pneumatic bones to reduce weight (v) Presence of additional air sacs to supplement. respiration Question 12: Could the number of eggs or young ones produced by an oviparous and viviparous mother be ‘equal? Why? ANSWER: The numbers of eges produced by an oviparous mother will be more than the young ones produced bya viviparous mother. This is because in oviparous animals, the development of young ones takes place outside the mother’s body. Their eggs are more prone to environmental conditions and predators ‘Therefore, to overcome the loss, more eggs are produced by mothers so that even under harsh environmental conditions, some eggs might be able to survive and produce young ones. On the other hand, in viviparous organisms, the development of young ones takes place in safe conditions inside the body of the mother. They are less exposed to environmental conditions and predators. Therefore, there are more chances of their survival and hence, Jess number of young ones is produced compared to the number of eggs.Question 13: Segmentation in the body is first observed in which of the following: (@) Platybelminthes (b) Aschelminthes (c) Annebda (d) Arthropoda ANSWER: The body segmentation first appeared in the phykim, Annelida (anmulus meaning lithe ring). Question 14: Match the following: (@) Operculam @ Crenophora @) Parapoda |G Motusca [eo Seaks | (a) Porifera @ Comb plates | (wy Repaiia © Radula ©) Annelida @ Fas (A Cycostomata_and Chondrichihyes ® Choanoeytes | (i) Mammalia @) Gil sits (ii) Ostechihyes ANSWER: ‘Comm T Colarmn T @ | Opercukim | (wi [ Osteichihyes (b) | Parapodia |) _[ Annelida (© | Seaks: )_| Reptilia @ | Comb phates |@ | Ctenophora © | Radula | Motisca © | airs (i)_| Mamata (@ | Choanoeytes | (ia) _| Porifera ey | Gil sts [| Cyctostomata_and Chondiichihyes Question 15: Prepare a ist of some animals that are found parasitic on human beings. ANSWER: Taenia solium Platyhelminthes Fasciola hepatica __| Platyhelminthes “Ascaris lumbricoides_| Aschelminthes Wuchereria bancrofit | Aschelminthes “Ancyclostoma ‘Aschelminthes 16 Diflerentiate_between chondrichthyes_and osteichthyes? Chondrichthyes Osteichthyes_1. The members of class chondrichthyes posses cartilaginous endoskeleton ‘Their skin bears placoid scales ‘Mouth is located ventrally ‘The gill: sits are without and operculum. ‘They lack air bladder. Fertibation is internal ‘Many members are viviparows. sep saw ‘The members of chss osteichthyes have boney endoskeleton. ‘Their skin is covered with cycloid/ctenoid scales. ‘The mouth is mostly terminal ‘The gills are covered by an operculum on each side, ‘They posses air bladder Fertilisation is external ‘They are mostly oviparous. 17. Match the following: fa. Amphibia 1 tA Bindder lb. Mommets ii cartilaginous notochord lc. Chondrichthyes iii Mammary glands a. Omkidoes jv, Pneumatic bones fe Gyionieats v. Dual habitat Pes vi Mouth without jaws Ans. ay, d- 18. Draw a labeled diagram of cnidoblast . Mention its two functions, Ref. fig.4.7 NCERT Text book. Chidoblasts are used by cnidarians for anchorage, defense and for the capture of the pray. 19. Creative and critical thinking. Birds are vertebrates with wings and feathers, Most birds can fly ,using power full muscles to flap their wings. But a few bird species do not have strong, enough wings to fly, and so these birds are flightless. Binds occur everywhere in the fields, forest, deserts, mountains and water, poss etc. They exhibit a verity of behaviors. They produce peculiar sound and communicate with the each other by songs and bindcall.. Answer the following questions retated to birds. 1. Name a flightless bird. 2. Give any two features in which birds resemble with mamma. 3. Write two features in which birds resemble with reptiles. Answers: 1. Ostrich(Struthio) 2. Both are warm blooded animals, both have four chambered heart. 3. The body of reptiles is covered by comified scales, Birds have scales only on their hind limbs, Both are oviparous animals.(Except some snakes)