{"id":24871,"date":"2023-09-16T11:58:14","date_gmt":"2023-09-16T06:28:14","guid":{"rendered":"https:\/\/apboardsolutions.com\/?p=24871"},"modified":"2023-09-19T15:42:13","modified_gmt":"2023-09-19T10:12:13","slug":"ap-inter-1st-year-zoology-notes-chapter-3","status":"publish","type":"post","link":"https:\/\/apboardsolutions.com\/ap-inter-1st-year-zoology-notes-chapter-3\/","title":{"rendered":"AP Inter 1st Year Zoology Notes Chapter 3 Animal Diversity-I: Invertebrate Phyla"},"content":{"rendered":"

Students can go through\u00a0AP Inter 1st Year Zoology Notes<\/a> 3rd Lesson Animal Diversity-I: Invertebrate Phyla will help students in revising the entire concepts quickly.<\/p>\n

AP Inter 1st Year Zoology Notes 3rd Lesson Animal Diversity-I: Invertebrate Phyla<\/h2>\n

1. Phylum – Porifera :<\/span><\/p>\n

\u2192 Sponges are the only metazoans that lacks true embryological germ layers.<\/p>\n

\u2192 Highly totipotent nature of cells and presence of aquiferous system are two unique features of sponges.<\/p>\n

\u2192 Pinacoderm and choanoderm are the two-epitheloid layers in sponges.<\/p>\n

\u2192 Water current is maintained by the beating of choanocytes flagella.<\/p>\n

\u2192 Water (eaves spongeoceol through osculum.<\/p>\n

\u2192 Canal system helps in food collection, respiration and excretion.<\/p>\n

\"AP<\/p>\n

\u2192 Archaeocytes are totipotent cells.<\/p>\n

\u2192 Digestion is completely intracellular and occurs in Choanocytes and Archaeocytes.<\/p>\n

\u2192 Sponges have powers of regeneration and cell aggregation.<\/p>\n

\u2192 Sponges are the only metazoans without nerve cells.<\/p>\n

\u2192 Sponges are the suspension feeders.<\/p>\n

\u2192 Asexual reproduction is by fragmentation, budding and by gemmules.<\/p>\n

\u2192 Development is indirect.<\/p>\n

\u2192 Porifera is classified into three classes, they are, calcarea, hexactinellida and demospongia.<\/p>\n

\u2192 Sponges are sequential hermaphrodites, they exhibit protogyny or protandry.<\/p>\n

\u2192 Fertilization occurs mesophyl. Sponges show indirect development as it includes larval forms.<\/p>\n

\u2192 Choanocytes of sponges resemble those of Proterospongia.<\/p>\n

2. Phylum – Cnidaria :<\/span><\/p>\n

\u2192 Cnidarians are diploblastic eumetazoans with tissue grade organization.<\/p>\n

\u2192 Cnidarians are characterized by the presence of cnidocytes, polypoid and medusoid forms.<\/p>\n

\u2192 Coral reefs are the large formation of calcium carbonate laid down by certain anthozoan corals in shallow tropical seas.<\/p>\n

\u2192 Cnidarians show radial symmetry, sea anemones exhibit biradial symmetry. Polyp is sessile while medusa is free-swimming.<\/p>\n

\"AP<\/p>\n

\u2192 Polyp is sessile with a mouth-up orientation. Medusa is umbrella or bell-shaped with a mouth-down orientation.<\/p>\n

\u2192 Mesoglea contains amoeboid cells derived from ectoderm.<\/p>\n

\u2192 Gastrovascular cavity helps in digestion and circulation. Digestion is first extra-cellular and then intra-cellular.<\/p>\n

\u2192 Medusoid forms have statocysts. Diffused conduction of nerve impulse occurs.<\/p>\n

\u2192 Hydrozoans medusae are craspedote whereas scyphozoan medusae are acraspedote.<\/p>\n

\u2192 In medusa, mesoglea is important in buoyancy.<\/p>\n

\u2192 In scyphozoans, scyphistoma produces ephyrae by strobilation.<\/p>\n

\u2192 Mesoglea is cellular in Scyphozoa and Anthozoa.<\/p>\n

\u2192 In anthozoans the inner free margin of mesentery is produced into aconitum that bears cnidocytes.<\/p>\n

\u2192 Class Scyphozoa includes jellyfish.<\/p>\n

\u2192 Class Anthozoa includes sea anemones, corals.<\/p>\n

3. Phylum – Ctenophora :<\/span><\/p>\n

\u2192 Ctenophores are commonly known as sea walnuts or comb jellies or sea gooseberries.<\/p>\n

\u2192 These all are exclusively marine forms.<\/p>\n

\u2192 Body is radially symmetrical.<\/p>\n

\u2192 These are diploblastic organisms and tissue level of organisation. .<\/p>\n

\u2192 Locomotion by eight external rows of ciliated comb plates, hence the name ctenophora.<\/p>\n

\"AP<\/p>\n

\u2192 Food capture by the help of glue cells called lasso cells or colloblasts.<\/p>\n

\u2192 Well-marked character of ctenophores is Bioluminescence.<\/p>\n

\u2192 These are bisexual and reproduction is by sexual method.<\/p>\n

\u2192 Fertilisation is external, Development is indirect and includes a larval stage called cydippid larva.
\nEx : Plourobrachia, Hormiphora.<\/p>\n

4. Phylum – Platyhelmenthes :<\/span><\/p>\n

\u2192 These are triploblastic, bilaterally symmetrical Acoelomates.<\/p>\n

\u2192 They show cephalization and organ-system grade organization. Body cavity is absent.<\/p>\n

\u2192 Protonephredia are primarily osmoregulatory and secondarily excretory in function.<\/p>\n

\u2192 In tubellarians, body is covered by ciliated epidermis that secrets rod-shaped inclusions called rhabdoids.<\/p>\n

\u2192 In larger turbellarians, branched gut facilitates transport of nutrients to all parts of the body.<\/p>\n

\u2192 Body is covered by tegument in Trematodes and Cestodes.<\/p>\n

\u2192 Nervous system is ladder-like. They are mostly hermaphrodites and fertilization is internal.<\/p>\n

\u2192 Planarians have remarkable ability of regeneration due to totipotent cells called neoblasts. Muller’s larva or Goetfs larva present in some.<\/p>\n

\"AP<\/p>\n

\u2192 Flukes are ectoparasites or endoparasites. Body is covered by tegument.<\/p>\n

\u2192 Tapeworms are endoparasites. They exhibit pseudometamerism. Strobila is divided into proglottides.<\/p>\n

\u2192 Trematodes and Cestoda are placed under the taxon Neodermata. In these flatworms body is covered by a non ciliated, syncytial neodermis.<\/p>\n

5. Phylum – Nematods :<\/span><\/p>\n

\u2192 Nematodes are characterized by a species – specific number of cells or nuclei.<\/p>\n

\u2192 Tissues are cellular or syncytial.<\/p>\n

\u2192 Body cavity is a pseudocoelom; it is not lined by mesodermal peritoneum.<\/p>\n

\u2192 Digestion is extracellular and intracellular.<\/p>\n

\u2192 Excretory system includes excretory glands or H – shaped excretory canal system or both. Nervous system is intraepithelial.<\/p>\n

\u2192 Sense organs include amphids and phasmids. Nematodes are mostly unisexual and sexually dimorphic.<\/p>\n

\u2192 Development includes four moulds. Nematodes exhibit eutely.<\/p>\n

\u2192 Nematoda is classified into two classes. In Aphasmidia amphids are of various shapes. Phasmids are absent.<\/p>\n

\"AP<\/p>\n

\u2192 Excretory glands are present but excretory glands or excretory canals or both are present.<\/p>\n

\u2192 Eutely is a phenomenon in which cell divisions cease near the end of embryonic development so that number of cells of the adult is constant.<\/p>\n

6. Phylum – Annelida :<\/span><\/p>\n

\u2192 Annelids are triploblastic, bilaterally symmetrical, schizocoelomates protostomes.<\/p>\n

\u2192 Metamerism increased the efficiency of burrowing and also resulted in independent movements of the segments.<\/p>\n

\u2192 In annelids cephalization is more pronounced.<\/p>\n

\u2192 Coelomic cavities of adjacent segments are separated by intersegmental septa whereas the two coelomic cavities of a segment are separated from each other by mesenteries.<\/p>\n

\u2192 Growth results from the addition of new segments from growth zone located just in front of pygidium.<\/p>\n

\u2192 In many polychaetes parts of Parapodia are modified into gills.<\/p>\n

\u2192 In all non-chordates respiratory pigment, (if present), is present dissolved in the blood plasma, unlike in chordates where it occurs in certain blood corpuscles.<\/p>\n

\"AP<\/p>\n

\u2192 Excretory organs are meta-nephridia that opens into coelom by a nephrostome and to the exterior by a nephridiopore.<\/p>\n

\u2192 During metamorphosis the larval episphere becomes the Prostomium, here as the apart posterior to the telotroch becomes the pygidium. Trunk segments arise from a growth zone anterior to the telotroch.<\/p>\n

\u2192 Leeches have a fixed number of segments that show superficial annuli, fill Intersegmental septa and mesenteries are absent in leeches.<\/p>\n

\u2192 Clitellum is conspicuous only during reproductive periods in leeches.<\/p>\n

\u2192 In leeches coelom is reduced due to the presence of nutrient storing botryoidal tisse.<\/p>\n

\u2192 Leeches are copulating hermaphrodites with a penis whereas earthworms are copulating hermaphrodites without penis.<\/p>\n

\u2192 Development is direct.<\/p>\n

7. Phylum – Arthropoda :<\/span><\/p>\n

\u2192 Arthropoda is the largest phylum in Animalia.<\/p>\n

\u2192 They exhibit Heteronomous Metamerism and tagmosis.<\/p>\n

\u2192 They possess jointed appendages, striated muscles, and chitinous cuticle.<\/p>\n

\u2192 The chitinous cuticle offers protection and prevents loss of water from the body.<\/p>\n

\u2192 Haemocoel is the functional body cavity.<\/p>\n

\u2192 Alimentary canal consists of foregut, midgut and hindgut.<\/p>\n

\u2192 Respiratory gas exchange occurs through general body surface or gills or book gills or book lungs or tracheae.<\/p>\n

\u2192 Excretory organs are coxal glands, green glands and rrialpighian tubules.<\/p>\n

\"AP<\/p>\n

\u2192 Nervous system includes a nerve ring and double ventral nerve cord.<\/p>\n

\u2192 Centipedes are pisthogoneate (genital aperture at the posterior end of the trunk).<\/p>\n

\u2192 Millipedes are progoneates (genital aperture at the anterior end of the trunk).<\/p>\n

\u2192 In insects thorax bears three parts of jointed legs.<\/p>\n

\u2192 Urecotelic is a water conservation adaptation in insects.<\/p>\n

\u2192 Myriapoda and hexapoda are grouped under the infra phylum tracheata.<\/p>\n

\u2192 Chilopoda includes centipedes.<\/p>\n

\u2192 Diplopoda includes millipedes.<\/p>\n

\u2192 Hexapoda includes insects.<\/p>\n

8. Phylum – Mollusca :<\/span><\/p>\n

\u2192 Mollusca are the second largest animal phylum.<\/p>\n

\u2192 Gastropods are the secondarily asymmetrical.<\/p>\n

\u2192 Body is covered by a calcareous shell secreted by the mantle epithelium.<\/p>\n

\u2192 The space between mantle and visceral mass is called mantle cavity or pallial cavity.<\/p>\n

\u2192 Buccal cavity contains a rasping structure called Radula, except in the bivalves.<\/p>\n

\u2192 A crystalline style composed of digestive enzymes is present in the stomach of bivalves and some gastropods.<\/p>\n

\u2192 Second gills are formed by the folding of mantle epithelium.<\/p>\n

\u2192 Atria receives oxygenated blood from the gills.<\/p>\n

\"AP<\/p>\n

\u2192 Osphradium is a chemoreceptor, which helps in detection of the quality of water.<\/p>\n

\u2192 In most species, TrochOphore develops into a veligar larva.<\/p>\n

\u2192 Foot in aplacophorans, if present, is a fold that lies in the pedal groove.<\/p>\n

\u2192 Nervous system is ladder-like in aplacophorans and polyplacophorans.<\/p>\n

\u2192 In Chiton shell is divided into eight shell valves.<\/p>\n

\u2192 Neopilina is considered as a living fossil.<\/p>\n

\u2192 Heart of monoplacophorans is unique with two pairs of atria opening into a pair of ventricles.<\/p>\n

\u2192 Serial repetition of internal organs in several systems is one of the most striking features of monoplacophorans.<\/p>\n

\u2192 Gastropoda is the largest and the most diverse molluscan class.<\/p>\n

\u2192 Only left nephridium, atrium and gills are present in most living gastropods.<\/p>\n

\u2192 Gills of bivalves are plate like and help in filter feeding or suspension feeding.<\/p>\n

\u2192 Development of fresh water bivalves includes a specialized veligar called glochidium larva which is ectoparasitic on the gills of fish.<\/p>\n

\u2192 Gills, atria and nephridia are one pair each in dibranchiates and two pairs each in tetrabranchiates.<\/p>\n

\u2192 Eyes of cephalopods are superficially similar to those of vertebrates.<\/p>\n

\u2192 Mollusca classified into seven classess. They are<\/p>\n

    \n
  1. Aplacophora.<\/li>\n
  2. Polyplacophora,<\/li>\n
  3. Monoplacophora,<\/li>\n
  4. Gastropoda,<\/li>\n
  5. Scaphopoda,<\/li>\n
  6. Pelecypoda and<\/li>\n
  7. Cephalopoda.<\/li>\n<\/ol>\n

    \"AP<\/p>\n

    \u2192 It develops into a veligar larva.<\/p>\n

    9. Phylum – Echinodermata :<\/span><\/p>\n

    \u2192 These are free-living animals. They are primarily bilaterally symmetrical.<\/p>\n

    \u2192 Endoskeleton consists of calcareous ossicles located in the dermis.<\/p>\n

    \u2192 Pedicellariae are compound ossicles useful for defense and cleaning the body.<\/p>\n

    \u2192 Body cavity is enterocoelom. Water vascular system is derived from coelom.<\/p>\n

    \u2192 Tube feet are useful in locomotion, food capture, gas exchange and excretion.<\/p>\n

    \u2192 Blood vascular system is of open type and is poorly developed.<\/p>\n

    \u2192 Excretory wastes diffuse out through respiratory surface.<\/p>\n

    \u2192 Nervous system lacks ganglia.<\/p>\n

    \u2192 A hypothetical larva called Dipleurula is considered as the ancestor for all echinoderm.<\/p>\n

    \u2192 In feather stars, free-swimming doliolaria and sessile pentacrinoid larva occur in life history.<\/p>\n

    \u2192 Auricularia larva, doliolaria larvae occur in life history of sea cucumbers.<\/p>\n

    \u2192 Bipinnaria and brachilaria larvae occur in life history of starfish.<\/p>\n

    \u2192 Oral surface is upward in Pelmatozoa but downward in Eleutherozoa.<\/p>\n

    \u2192 Anus is present on oral surface in Crinoidea, absent in Ophiuroidea.<\/p>\n

    \"AP<\/p>\n

    \u2192 Madreporite is absent in Crinoidea, oral in Ophiuroidea and is internal in Holothuroidea.<\/p>\n

    \u2192 Sea lilies are stalked arid sessile.<\/p>\n

    10. Phylum – Hemichordata :<\/span><\/p>\n

    \u2192 These are a small group of worm-like marine animals.<\/p>\n

    \u2192 These are bilaterally symmetrical, triploblastic and Coelomate animals.<\/p>\n

    \u2192 The body is cylindrical and composed of an anterior proboscis, a collar and a long trunk.<\/p>\n

    \u2192 The stomochord is present (once believed to be the notochord).<\/p>\n

    \u2192 Circulatory system is of open type with a dorsal heart.<\/p>\n

    \u2192 Respiration takes place by paired gill slits.<\/p>\n

    \u2192 Development is indirect and includes a tornaria larve.
    \nEx : Balanoglossus (acron worm), Saccoglossus.<\/p>\n

    \"AP<\/p>\n

    \u2192 Amphids : They are the cuticular depressions present on the lips surrounding the mouth in the nematodes. They are well developed in free living nematodes and serve as chemoreceptors.<\/p>\n

    \u2192 Autotorpy : It is the process of voluntary breaking of the injured part of the body (self mutilation or amputation). It is a device developed to protect the body from the enemies and parasites as seen in the echinoderms .<\/p>\n

    \u2192 Bothridia : The leaf like organs present on the scolex of certain cestodes. They act as the . organs of attachment to the body parts of the host.<\/p>\n

    \u2192 Cercaria : It is a free swimming larva consisting of an ovoid body and a tail. It occurs in the life history of liver flukes.<\/p>\n

    \u2192 Choanopyte : It is a specialized flagellated cell with a cup shaped collar around the base of the flagellum. It maintains the current of water through the body.<\/p>\n

    \u2192 Clitellum : It is a belt or girdle shaped thickening of the skin, in a specific region of the body (14 to 16 segments in Pheretima). It secretes the cocoon and albumen (food for the developing young one), during the breeding season.<\/p>\n

    \u2192 Cocoon : It is a bag like structure secreted by the clitellum. Eggs and sperms are deposited into it. Fertilization and development occurs within the cocoon.<\/p>\n

    \u2192 Comb plates : They are ciliated plates helping in locomotion in the ctenophores.<\/p>\n

    \u2192 Ctenidia : They are the respiratory organs of molluscs. Each ctenidium (gill) consists of a central axis and one or two rows of filaments.<\/p>\n

    \u2192 Flame cell : It is a hollow cell containing a tuft of cilia in the inner space. It is excretory and osmoregulatory in function. Flame cell is a primitive type of excretory organ (protonephridium).<\/p>\n

    \"AP<\/p>\n

    \u2192 Gemmules : They are the ‘internal buds’ of some sponges aiding in asexual reproduction. They also help tide over unfavourable conditions.<\/p>\n

    \u2192 Juvenile : It is an immature young form resembling the adult in all aspects.<\/p>\n

    \u2192 Madreporite : It is a circular porous plate, present in the body of most echinoderms. Through its pores sea water enters the water vascular system.<\/p>\n

    \u2192 Mesenteries : They are vertical partitions dividing the coelenteron of sea anemones. They are developed as inward folds of the endoderm. They bear cnidoblasts.<\/p>\n

    \u2192 Miracidium : It is a free swimming larva of liver fluke. It contains ciliated epidermis, penetration glands, etc. It transforms into the sporocyst stage in the body of freshwater snail, which is the invertebrate host of liver fluke.<\/p>\n

    \u2192 Moulting or Ecdysis : It is the process of casting off the outer body wall. During development of nematode larvae, the cuticle is cast off 4 times.<\/p>\n

    \u2192 Mullers larva : It is the characteristic larva of turbellarians. It bears an apical tuft of cilia. Nephridia : They are highly coiled excretory organs derived from the ectoderm.<\/p>\n

    \u2192 Osculum : It is a large opening present at the free end of a sponge body. Water from the spongocoel flows out through the osculum.<\/p>\n

    \u2192 Ostia : They are numerous openings present on the body of a sponge. Water is drawn in through the ostia and sent out through the osculum (choanocytes play an important role in drawing in water).<\/p>\n

    \u2192 Parapodia : They are hollow biramous appendages of polychaetes. They bear tufts of many setae and help in locomotion.<\/p>\n

    \u2192 Parenchymula : It is the larva of sponges such as Clathrina. It is similar to the planula of cnidarians. It is covered with cilia all over.<\/p>\n

    \u2192 Pedicellariae : They are ‘forceps like structures’ (modified spines) in the body of sea stars and sea urchins . They remove foreign particles that may settle on the body surface and thus help in keeping the body surface clean.<\/p>\n

    \"AP<\/p>\n

    \u2192 Phasmids : They occur in some nematodes. They are well developed in parasitic nematodes and are glandulosensory in function.<\/p>\n

    \u2192 Planula : It is a ciliated, double walled, free swimming larva characteristic of a cnidarian.<\/p>\n

    \u2192 Polyembryony : Formation of several young ones from a single zygote. It occurs during the formation of redia and cercaria larvae in the life history of a liver fluke.<\/p>\n

    \u2192 Poyp or Hydranth : It is a flower shaped or hydra shaped zooid of the colonial cnidarians such as Obelia. It bears several tentacles around the mouth. It is a nutritive zooid.<\/p>\n

    \u2192 Radula : It is a thin ribbon shaped body lying in the buccal cavity of molluscs. It consists of a median stalk and two lateral lobes. Each lobe bears many rows of chitinous teeth. Radula works like a ‘file’ and rasps the vegetable food.<\/p>\n

    \u2192 Redia : It is an elongated larva of liver fluke produced by the sporocyst asexually\/ partheno- genetically. It gives rise to the second generation of rediae or the cercaria larvae.<\/p>\n

    \u2192 Rhabdites : They are rod shaped bodies present in the epidermal cells of turbellarians. On discharge they form a slimy (mucus) substance helping in locomotion by smoothening the path of gliding movement and also in defence.<\/p>\n

    \u2192 Setae : They are small, \/\u2018-shaped, chitinous structures present in the pits (setal sacs) of the body wall of earthworms. They aid in locomotion. In some, setae are modified into ‘penial setae’ and help in copulation.<\/p>\n

    \u2192 Spicules of a sponge : They are the supporting structures of the body secreted by scleroblasts. They are of different shapes and sizes. They are made up of calcium carbonate or silica.<\/p>\n

    \u2192 Spongocoel: It is the large central cavity of a sponge body.<\/p>\n

    \u2192 Statocyst: Statocyst is a sense organ concerned with the maintenance of equilibrium of the body.<\/p>\n

    \u2192 Syncytium : It is a multinucleate mass of protoplasm without any division into cells. The tegument of flatworms is syncytial.<\/p>\n

    \"AP<\/p>\n

    \u2192 Trichemella : It is a larval form characteristic of the hexactinellid sponges.<\/p>\n

    \u2192 Trochophore : It is the characteristic larva of annelids. It is ‘top’ shaped and bears one or more bands of cilia, an epical tuft, an eye etc. It contains coelom and nephridia. It is believed to be the forerunner of higher invertebrates.<\/p>\n

    \u2192 Zooid : It is a individual member of a ‘coelenterate’ colony. They serve different functions (division of labour).<\/p>\n

    \u2192 Invertebrate Phyla includes the animals which are without back bone.<\/p>\n

    \u2192 The invertebrates constitute about 90% of the known animals.<\/p>\n

    \u2192 Invertebrates are characterised by<\/p>\n

      \n
    1. a segmented body<\/li>\n
    2. Jointed appendages<\/li>\n
    3. Exoskeleton<\/li>\n
    4. Brain<\/li>\n<\/ol>\n

      \u2192 Invertebrate Phyla (Etymological meaning) – Examples:<\/p>\n

        \n
      1. Porifera (Pore bearing)- Sponges<\/li>\n
      2. Cnidaria (stinging nettle) – Hydra, Jellyfish, coral<\/li>\n
      3. Ctenophora (Comb bearing)-Comb Jellies<\/li>\n
      4. Platyhelminthes(Flat Worm) – Flat Worms<\/li>\n
      5. Nematoda (Thread like)-Round Worms<\/li>\n
      6. Annelida (Ringed) – Leeches<\/li>\n
      7. Arthropoda (Jointed Legs) – Spiders, Insects<\/li>\n
      8. Mollusca (Soft) – Octopus, Squid, Pila<\/li>\n
      9. Echinodermata (Spiny skinned) – Star Fish<\/li>\n
      10. Hemichordata (Half cord) – Acorn Worms<\/li>\n<\/ol>\n

        \u2192 Anthozoans are commonly called as sea anemones. [IPE]
        \nThey are sedentary marine animals.<\/p>\n

        \u2192 Polychaetes are marine annelids. They are commonly bristle worms or clam worms. [IPE]<\/p>\n

        \u2192 LimulUs(king crab) is the living fossil arthropod. The respiratory organs are book gills. [IPE]<\/p>\n

        \u2192 Crustaceans are aquatic mandibulate arthropods. [IPE]<\/p>\n

        \u2192 Aristotle’s lantern is a complex 5 jawed masticatory apparatus present in buccal cavity of sea urchins. Ex: Echinus (Sea urchin) [IPE]<\/p>\n

        \u2192 Echinoidea is a class of phylum echinodermata. [IPE]<\/p>\n

        \u2192 In case of poriferans, the spongocoel is lined with flagellated cells called choanocytes. [NEET-2017]<\/p>\n

        \u2192 Important characteristic that hemichordates share with chordates is pharynx with gill slits. [NEET-2017]<\/p>\n

        \u2192 Metagenesis refers to alternation of generation between asexual and sexual phases of an organism. [NEET-2015]<\/p>\n

        \u2192 Exoskeleton is mainly responsible for diversification of insects on land. [NEET-2015]<\/p>\n

        \u2192 Trichinella spiralis endoparasites of humans does show viviparity. [NEET-2015]<\/p>\n

        \u2192 Planaria possesses high capacity of regeneration. [NEET-2014]<\/p>\n

        \u2192 Cnidaria represents both marine and fresh water species. [NEET-2014]<\/p>\n

        \u2192 One of the representatives of phylum arthropoda is silver fish. [NEET-2013]<\/p>\n

        \u2192 Pheretima and its close relatives derive nourishment from decaying fallen leaves and soil organic matter. [2012 PMT]<\/p>\n

        \u2192 One very special feature in the earth worm Pheretima is that the typhlosole greatly increases the effective absorption area of the digested food in the intestine. [2011 PMT]<\/p>\n

        \u2192 Flatworms are triploblastic. [2010 PMT]<\/p>\n

        \u2192 An example of animal having a single opening to the outside that serves both as mouth as well as anus is Fasciola. [2010 PMT]<\/p>\n

        \u2192 If a live earthworm is pricked with a needle on its outer surface without damaging its gut, the fluid that comes out is coclomic fluid. [2009 PMT]<\/p>\n

        \u2192 A group of animals Aschelminthes (round worms) is bilaterally symmetrical and triploblastic. [2009 PMT]<\/p>\n

        \u2192 Ascaris is characterised by presence of neither true coelom nor metamerism. [2008 PMT]<\/p>\n","protected":false},"excerpt":{"rendered":"

        Students can go through\u00a0AP Inter 1st Year Zoology Notes 3rd Lesson Animal Diversity-I: Invertebrate Phyla will help students in revising the entire concepts quickly. AP Inter 1st Year Zoology Notes 3rd Lesson Animal Diversity-I: Invertebrate Phyla 1. Phylum – Porifera : \u2192 Sponges are the only metazoans that lacks true embryological germ layers. \u2192 Highly … Read more<\/a><\/p>\n","protected":false},"author":5,"featured_media":39165,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":""},"categories":[13],"tags":[],"jetpack_featured_media_url":"https:\/\/apboardsolutions.com\/wp-content\/uploads\/2022\/09\/Chapter-3-Animal-Diversity-I-Invertebrate-Phyla.png","_links":{"self":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts\/24871"}],"collection":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/comments?post=24871"}],"version-history":[{"count":5,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts\/24871\/revisions"}],"predecessor-version":[{"id":50154,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/posts\/24871\/revisions\/50154"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/media\/39165"}],"wp:attachment":[{"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/media?parent=24871"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/categories?post=24871"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/apboardsolutions.com\/wp-json\/wp\/v2\/tags?post=24871"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}