Animal Kingdom PDF Notes

Animal Kingdom © 2022, Aakash BYJU'S. All rights reserved. Key Takeaway Characteristics of animals 1 Levels of organisation Symmetry Germ layer organisation Coelom Segmentation Notochord Circulatory system Digestive system 2 Phylum Porifera © 2022, Aakash BYJU'S. All rights reserved. 3 Classificatio...

Animal Kingdom © 2022, Aakash BYJU'S. All rights reserved. Key Takeaway Characteristics of animals 1 Levels of organisation Symmetry Germ layer organisation Coelom Segmentation Notochord Circulatory system Digestive system 2 Phylum Porifera © 2022, Aakash BYJU'S. All rights reserved. 3 Classification of animals Key Takeaway Phylum Coelenterata 4 5 Phylum Platyhelminthes 6 7 Phylum Annelida Phylum Arthropoda 10 11 © 2022, Aakash BYJU'S. All rights reserved. Phylum Aschelminthes 8 9 Phylum Mollusca Phylum Ctenophora Phylum Echinodermata Key Takeaway 12 Phylum Chordata 13 Subphylum Vertebrata Class Cyclostomata Class Chondrichthyes Class Osteichthyes Class Amphibia Class Reptilia Class Aves Class Mammalia Summary © 2022, Aakash BYJU'S. All rights reserved. Phylum Hemichordata Classification of Animals Classification of animals is important as the diversity of animals is huge. It also helps in assigning a systematic position to newly discovered species. Basis of classification Symmetry Levels of organisation Germ layer organisation © 2022, Aakash BYJU'S. All rights reserved. Coelom Respiratory system Notochord Segmentation Circulatory system Levels of Organisation Cellular level of organisation: In lower animals such as sponges, cells aggregate together to exhibit cellular level of organisation. Tissue level of organisation: Cells which perform similar functions are grouped together to form tissues (E.g. - Coelenterates). Levels of organisation Organ system Organ Tissue Organ level of organisation: Several tissues together form the organ (E.g. - members of Platyhelminthes) Organ system level of organisation: Several organs combine to form the organ system (E.g. - humans). © 2022, Aakash BYJU'S. All rights reserved. Cell Symmetry Symmetry refers to a correspondence of body parts, in size, shape and relative position, on opposite sides of a dividing line or distributed around a central point or axis. Radial Body can be divided into two identical halves in any plane passing through the centre. E.g., starfish. © 2022, Aakash BYJU'S. All rights reserved. Bilateral Body can be divided into identical two halves in only one plane. E.g., goat. Asymmetry Body cannot be divided into two equal halves in any plane. E.g., sponges (irregular). Germ Layer Organisation Germ layer is a layer of cells in an embryo. It contributes to the formation of all organs and tissues. Germ layer organisation Diploblastic External ectoderm Mesoglea Internal endoderm Coelenterates © 2022, Aakash BYJU'S. All rights reserved. Triploblastic Ectoderm Mesoderm Endoderm Platyhelminthes to chordates Coelom A body cavity present between the alimentary canal and body wall. The cavity is lined externally by mesoderm. Acoelomate Pseudocoelomate Eucoelomate Platyhelminthes Aschelminthes Annelida to chordata Organisms that do not have coelom For e.g. - Flatworms Organisms which have a cavity, but it is not lined by the mesoderm For e.g. - Roundworms © 2022, Aakash BYJU'S. All rights reserved. Organisms that have coelom For e.g. - Human beings Segmentation Based on the absence or presence of segments in their body, the organisms are classified into- segmented and unsegmented. In organisms like earthworm, the body is divided into segments with serial repetition of some organs. This type of segmentation is known as metameric segmentation. Metameric segmentation in earthworm © 2022, Aakash BYJU'S. All rights reserved. Notochord Derived from the mesoderm Rod-like structure on the posterior side of the embryo Found during embryonic development Chordates Notochord Animals with notochord Non-chordates Animals without notochord © 2022, Aakash BYJU'S. All rights reserved. Circulatory and Digestive System Based on the number of openings, digestive system is classified as: Complete digestive system: Separate opening for mouth and anus E.g. - Aschelminthes to chordates. Incomplete digestive system: One common opening for mouth and anus E.g. - Platyhelminthes. Based on the presence and absence of blood vessels, circulatory system is classified into: Open circulatory system: Blood pumped from heart directly bathes cell and tissues Closed circulatory system: Blood flows through definite vessels throughout © 2022, Aakash BYJU'S. All rights reserved. Classification of Animals Kingdom Level of organisation Cellular level Animalia (multicellular) Symmetry Mostly symmetrical Radial Coelom Phylum Acoelomates Porifera Coelenterata (Cnidaria) Acoelomates Ctenophora Acoelomates Platyhelminthes Pseudocoelomates Aschelminthes Tissue/ Organ/ Organ system Bilateral Coelomates Annelida Arthropoda Mollusca Echinodermata Hemichordata © 2022, Aakash BYJU'S. All rights reserved. Chordata Phylum Porifera Characteristic features Mostly marine (Sycon), some freshwater (Spongilla) forms are also present Sedentary and asymmetrical Primitive and show cellular level of organisation Water enters through minute pores (ostia) in the body wall into a central cavity, spongocoel, from where it goes out through the osculum Water canal system- to feed, respire and remove waste Choanocytes or collar cells line the spongocoel and the canals Digestion is intracellular Presence of spicules and spongin fibres to support and protect itself © 2022, Aakash BYJU'S. All rights reserved. Osculum Choanocyte Spongocoel Phylum Porifera Asexual Fragmentation Reproduction in sponges Sexes are not separate (hermaphrodite) Fertilisation is internal Examples: Sycon (Scypha), Spongilla (Freshwater sponge) and Euspongia (Bath sponge) Sexual Formation of gametes © 2022, Aakash BYJU'S. All rights reserved. Development - indirect having a larval stage which is morphologically distinct from the adult Phylum Coelenterata Characteristic features Aquatic- mostly marine Sessile or free swimming Radially symmetrical Stinging capsules called cnidocytes are present on the tentacles and the body o Used for anchorage, defense and for the capturing prey Tissue level of organisation and diploblastic Digestion : Extracellular and intracellular They have a central gastrovascular cavity with a single opening, mouth on hypostome Some of the cnidarians, e.g., corals have a skeleton composed of calcium carbonate © 2022, Aakash BYJU'S. All rights reserved. Phylum Coelenterata Basic body forms Alternation of generation Polyp Medusa Sessile, cylindrical form E.g.- Hydra, Adamsia Umbrella shaped and free swimming E.g. - Aurelia © 2022, Aakash BYJU'S. All rights reserved. Cnidarians which exist in both forms exhibit alternation of generation. It is also known as metagenesis. In Obelia o Polyps produce medusae asexually. o Medusae form the polyps sexually. Examples: Physalia (Portuguese manof-war), Adamsia (Sea anemone), Pennatula (Sea-pen), Gorgonia (Seafan) and Meandrina (Brain coral) Phylum Ctenophora Characteristic features Exclusively marine, also known as sea walnuts or comb jellies Radially symmetrical, diploblastic, tissue level of organisation Digestion: Extracellular and intracellular Hermaphrodites: Sexes are not separate 8 external rows of ciliated comb plates used for locomotion o Hence, they are also called comb jellies Bioluminescence: Property of a living organism to emit light Only sexual reproduction Retractile tentacle Anal canal Ciliary comb plate Mouth Pleurobrachia External fertilization with indirect development © 2022, Aakash BYJU'S. All rights reserved. Pleurobrachia and Ctenoplana Bioluminescent comb jellies Phylum Platyhelminthes Characteristic features They have dorsoventrally flattened body: Flatworms Mostly endoparasites, only a few are free living Bilaterally symmetrical, triploblastic, acoelomates Organ level of organisation Hooks and suckers are present in the parasitic forms Flame cells: specialized excretory cells which help in osmoregulation and excretion Sexes are not separate Fertilisation - internal Development is through many larval stages Some members like Planaria possess high regeneration capacity Examples: Taenia (Tapeworm), Fasciola (Liver fluke) © 2022, Aakash BYJU'S. All rights reserved. Hook Sucker Nucleus Slit like openings Cilia Flame cell Phylum Aschelminthes Characteristic features Commonly known as roundworms Habitat: Terrestrial and Aquatic (both freshwater or marine) Either parasitic or free-living Organ system level of organisation Triploblastic and pseudocoelomate Bilaterally symmetrical Digestive system: Complete alimentary canal with a muscular pharynx Have excretory tube They are dioecious: Separate sexes; females longer than males, exhibit internal fertilization Development - direct (young ones look same as adults) or indirect (through a larval stage) © 2022, Aakash BYJU'S. All rights reserved. Ascaris Examples : Ascaris (Roundworm), Wuchereria (Filaria worm), Ancylostoma (Hookworm). Phylum Annelida Characteristic features Metamerically segmented worms Habitat: o Terrestrial (Earthworm) o Aquatic ▪ Freshwater - Leech ▪ Marine – Nereis Lifestyle: o Parasitic (Leech) o Free-living (Nereis) o Bilaterally symmetrical and triploblastic o True coelomates o Examples: Nereis, Pheretima (Earthworm) and Hirudinaria (Blood sucking leech) © 2022, Aakash BYJU'S. All rights reserved. Nereis (Free-living) Hirudinaria (Leech) (Parasitic) Phylum Annelida Organ-system level of organisation Circulatory system Excretory system Nervous system Dorsal vessel (Main heart) Auxiliary hearts Ventral vessels Closed circulatory system © 2022, Aakash BYJU'S. All rights reserved. Nephridia Nephridia help in osmoregulation and excretion Brain Nerve cord Consists of paired ganglia connected by lateral nerves to a double ventral nerve cord Phylum Annelida Locomotion: Longitudinal and circular muscles (Eg., Earthworm) Swimming: Parapodia (Eg., Nereis) Circular muscle Longitudinal muscle Coelomic cavity Sexual reproduction o Monoecious - Both sexes together (hermaphrodites) E.g., Earthworms, Leeches. o Dioecious - Separate sexes, E.g., Nereis. © 2022, Aakash BYJU'S. All rights reserved. Parapodia Phylum Arthropoda Characteristic features Largest phylum, includes insects Segmented body, bilateral symmetry, triploblastic, coelomate Chitinous exoskeleton: Skeleton outside the body Body divisions: Head, thorax and abdomen Jointed appendages (arthros- joint and podaappendages) Organ system level of organisation Open circulatory system Sensory organs: o Antennae o Eyes (compound and simple) o Statocysts or balancing organs are present Head Thorax Abdomen Body divisions Jointed appendages © 2022, Aakash BYJU'S. All rights reserved. Phylum Arthropoda Excretory system: Malpighian tubules © 2022, Aakash BYJU'S. All rights reserved. Phylum Arthropoda Mostly dioecious Fertilization is usually internal Mostly oviparous Development maybe direct or indirect Examples: o Economically important ArthropodsApis (Honey bee), Bombyx mori (Silkworm), Laccifer lacca (Lac insect) o Vectors– Anopheles, Culex and Aedes (Mosquitoes) o Gregarious pest– Locusta (Locust) o Living fossil– Limulus (King crab) Bombyx mori (Silk worm) Laccifer lacca (Lac insect) Honey bee © 2022, Aakash BYJU'S. All rights reserved. Phylum Mollusca Characteristic features Second largest animal phylum Habitat: o Terrestrial o Aquatic- Freshwater, Marine Bilateral symmetry, triploblastic and coelomate Usually dioecious and oviparous with indirect development Pila (Apple snail) Organ system level of organisation Unsegmented body covered with calcareous shell (Exception- Octopus) Examples: Pila (Apple snail), Pinctada (Pearl oyster), Sepia (Cuttlefish), Loligo (Squid), Octopus (Devil fish), Aplysia (Sea-hare), Dentalium (Tusk shell) and Chaetopleura (Chiton) © 2022, Aakash BYJU'S. All rights reserved. Octopus (Devil fish) Phylum Mollusca Distinct body: Head, muscular foot and visceral hump (visceral mass) Mantle: Spongy layer covering the visceral hump Mantle cavity: Space between hump and mantle in which feather like gills are present The anterior head region has sensory tentacles Mouth: Contains a file-like rasping organ for feeding called radula © 2022, Aakash BYJU'S. All rights reserved. Visceral mass Head Foot Phylum Echinodermata Characteristic features Marine Endoskeleton of calcareous ossicles; spiny bodied Symmetry o Adults: Radial o Larvae: Bilaterally. Organ system level of organisation, triploblastic, coelomates Water vascular system: Helps in locomotion, capture and transport of food and respiration Excretory system: Absent Digestive system: Complete with mouth on ventral and anus on the dorsal side Sexual reproduction, separate sexes Fertilisation is usually external and indirect development with free-swimming larva Examples: Asterias (Star fish), Echinus (Sea urchin), Antedon (Sea lily), Cucumaria (Sea cucumber) and Ophiura (Brittle star) © 2022, Aakash BYJU'S. All rights reserved. Asterias (Starfish) Phylum Hemichordata Characteristic features They have a rudimentary structure in the collar region called stomochord which resembles a notochord Worm-like marine animals Organ-system level of organisation Bilaterally symmetrical, triploblastic and coelomate Cylindrical body with anterior proboscis, a collar and a long trunk Circulatory system: Open type Respiration: Through gills Excretory organ: proboscis gland Sexes are separate Fertilisation is external Development is indirect Examples: Balanoglossus and Saccoglossus. © 2022, Aakash BYJU'S. All rights reserved. Saccoglossus Proboscis Collar Trunk Phylum Chordata Characteristic features Characterised by the presence of notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits Bilaterally symmetrical, triploblastic and coelomat Organ system level organisation. Show presence of post anal tail Circulatory system: Closed © 2022, Aakash BYJU'S. All rights reserved. Nerve cord Pharyngeal gill slits Notochord Post-anal tail Phylum Chordata Chordates Non-chordates Notochord present Notochord absent Central nervous system is dorsal, hollow and single Central nervous system is ventral, solid and double Pharynx perforated by gill slits Gill slits are absent Heart is ventral Heart is dorsal (if present) Post-anal tail present Post-anal tail absent © 2022, Aakash BYJU'S. All rights reserved. Phylum Chordata Phylum chordata is divided into three subphyla Urochordata/Tunicata Exclusively marine Notochord is present in the larval tail Eg: Ascidia, Salpa, Doliolum Cephalochordata Exclusively marine Notochord extends from head to tail region, and is persistent throughout their life Eg: Branchiostoma Protochordates Vertebrata Notochord present during embryonic development later replaced by bony vertebral column in adults Have a ventral muscular heart (2, 3 or 4 chambers) Kidneys for excretion and osmoregulation Paired appendages- fins or limbs All vertebrates are chordates but all chordates are not vertebrates © 2022, Aakash BYJU'S. All rights reserved. Subphylum Vertebrata Classification of vertebrata Division Agnatha (Lack jaw) Gnathostomata (Bear jaw) Super class Pisces (Bear fins) Class 1. Cyclostomata © 2022, Aakash BYJU'S. All rights reserved. Class 1. Chondrichthyes 2. Osteichthyes Tetrapoda (Bear limbs) Class 1. Amphibia 2. Reptilia 3. Aves 4. Mammals Class Cyclostomata Characteristic features Elongated body is devoid of scales and paired fins Have 6-15 pairs of gill slits for respiration Their larvae, after metamorphosis, return to the ocean Ectoparasites on some fishes Have sucking and circular mouth without jaws Cranium and vertebral column are cartilaginous Circulatory system: Closed type Marine but migrate for spawning to fresh water, die after few days Examples: Petromyzon (Lamprey) and Myxine (Hagfish) © 2022, Aakash BYJU'S. All rights reserved. Petromyzon (Lamprey) Class Chondrichthyes Characteristic features Marine, streamlined body with cartilaginous endoskeleton Notochord persistent throughout life Separate gill slits without operculum Tough skin with minute placoid scales Ventrally located mouth; Teeth are modified placoid scales Predaceous animals with powerful jaws Swim constantly to avoid sinking as air bladder is absent Two chambered heart; Poikilothermous (cold-blooded) Separate sexes, internal fertilisation, many are viviparous In males, pelvic fins bear claspers Some of them have electric organs (Torpedo) and some possess poison sting (Trygon) Examples: Scoliodon (Dog fish), Pristis (Saw fish), Carcharodon (Great white shark), Trygon (Stingray). © 2022, Aakash BYJU'S. All rights reserved. Carcharodon (The great white shark) Electron organ Central nervous system Torpedo Class Osteichthyes Characteristic features Both marine and freshwater fishes Bony endoskeleton and a streamlined body Terminal mouth Have 4 pairs of gills with an operculum on each side Skin is covered with cycloid/ctenoid scales Air bladder regulates buoyancy Heart is two-chambered; Poikilothermous (cold-blooded) Sexes are separate, external fertilisation Mostly oviparous and development is direct Examples: o Marine– Exocoetus (Flying fish), Hippocampus (Sea horse) o Freshwater– Labeo (Rohu), Catla (Katla), Clarias (Magur) o Aquarium– Betta (Fighting fish), Pterophyllum (Angel fish) © 2022, Aakash BYJU'S. All rights reserved. Labeo (Rohu) Gills covered by operculum Class Amphibia Characteristic features Amphibians can live in aquatic and terrestrial habitats (dual life) Most of them have two pairs of limbs Body division: Head and trunk (Tail may be present in some) Moist skin (without scales) Poikilotherms (cold-blooded) Sexes are separate, external fertilisation Oviparous and development is indirect Examples: Bufo (Toad), Rana (Frog), Hyla (Tree frog), Salamandra (Salamander), Ichthyophis (Limbless amphibia) Eyes with eyelids Tympanum represents the ear Alimentary canal, urinary and reproductive tracts open into a common chamber called cloaca which opens to the exterior Respiration: Gills, lungs and through skin. Heart: 3-chambered (two auricles and one ventricle) Frog © 2022, Aakash BYJU'S. All rights reserved. Class Reptilia Characteristic features Mostly terrestrial Body is covered by dry and cornified skin, epidermal scales or scutes No external ear openings, tympanum represents ear 2 pairs of limbs (if present) Heart: Usually three-chambered, but four-chambered in crocodiles. Poikilotherms Snakes and lizards shed their scales as skin cast Mode of locomotion: Creeping or crawling Sexes are separate, internal fertilisation Oviparous and development is direct Examples: o Chelone (Turtle), Testudo (Tortoise), Chameleon (Tree lizard), Calotes (Garden lizard), Crocodilus (Crocodile), Alligator (Alligator) o Hemidactylus (Wall lizard) o Poisonous snakes– Naja (Cobra), Bangarus (Krait), Vipera (Viper) © 2022, Aakash BYJU'S. All rights reserved. Chelone (Turtle) Class Aves Characteristic features Mostly they fly due to the presence of feathers (Exceptions- Ostrich, Kiwi) and possess beak Forelimbs: Modified into wings Hind limbs: Have scales and are modified for walking, swimming or clasping the tree branches Skin: Dry without glands except the oil gland at the base of the tail Endoskeleton: Fully ossified (bony) and the long bones are hollow with air cavities (pneumatic) Digestive tract: crop and gizzard (additional chambers) Heart: Four-chambered, homoiothermous (warm-blooded) © 2022, Aakash BYJU'S. All rights reserved. Crop Gizzard Digestive tract Oil glands Class Aves Respiration through lungs o Air sacs connected to lungs supplement respiration Sexes are separate Fertilisation is internal Oviparous and development is direct Examples : Corvus (Crow), Columba (Pigeon), Psittacula (Parrot), Struthio (Ostrich), Pavo (Peacock), Aptenodytes (Penguin), Neophron (Vulture) © 2022, Aakash BYJU'S. All rights reserved. Air pockets Air cavities Class Mammalia Characteristic features Habitats– Polar ice caps, deserts, mountains, forests, grasslands and dark caves (some of them have adapted to fly or live in water) Unique mammalian characteristic- Presence of milk producing glands (mammary glands) for the nourishment of young ones Two pairs of limbs- Adapted for walking, running, climbing, burrowing, swimming or flying. Skin- Possesses hair External ears or pinnae are present Different types of teeth are present in the jaw. Heart- Four-chambered Homoiothermous (warm-blooded) © 2022, Aakash BYJU'S. All rights reserved. Class Mammalia Respiration- Through lungs Examples: o Oviparous- Ornithorhynchus (Platypus) o Viviparous- Macropus (Kangaroo), Pteropus (Flying 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 (Lion) Sexes are separate, internal fertilisation Viviparous with few exceptions and development is direct © 2022, Aakash BYJU'S. All rights reserved. Platypus (Ornithorhynchus) Kangaroo (Macropus) Monkey (Macaca) Summary Phylum Level of organisation Symmetry Coelom Segmentation Digestive system Circulatory system Respiratory system Distinctive features Porifera Cellular Many Absent Absent Absent Absent Absent Body with pores and canal in walls Coelenterata (Cnidaria) Tissue Radial Absent Absent Incomplete Absent Absent Cnidoblasts present Ctenophora Tissue Radial Absent Absent Incomplete Absent Absent Comb plates for locomotion Platyhelminthes Organ & organ system Bilateral Absent Absent Incomplete Absent Absent Fat body, suckers Aschelminthes Organ system Bilateral Pseudo Absent Complete Absent Absent Often worm shaped, elongated © 2022, Aakash BYJU'S. All rights reserved. Summary Phylum Level of organisation Symmetry Coelom Segmentation Digestive system Circulator y system Respiratory system Distinctive features Annelida Organ system Bilateral Coelomate Present Complete Present Absent Body segmentation like rings Arthropoda Organ system Bilateral Coelomate Present Complete Present Present Exoskeleton of cuticle, jointed appendage Mollusca Organ system Bilateral Coelomate Absent Complete Present Present External skeleton shell usually present Echinodermata Organ system Radial (adults) Coelomate Absent Complete Present Present Water vascular system, radial symmetry Hemichordata Organ system Present Worm-like with proboscis, collar and trunk Bilateral © 2022, Aakash BYJU'S. All rights reserved. Coelomate Absent Complete Present Summary Chordates Non-chordates Notochord present Notochord absent Central nervous system is dorsal, hollow and single Central nervous system is ventral, solid and double Pharynx perforated by gill slits Gill slits are absent Heart is ventral Heart is dorsal (if present) Post-anal tail present Post-anal tail absent © 2022, Aakash BYJU'S. All rights reserved. Summary Kingdom animalia Porifera Ctenophora Coelenterata Aschelminthes Platyhelminthes © 2022, Aakash BYJU'S. All rights reserved. Arthropoda Annelida Echinodermata Mollusca Chordata Hemichordata Summary Classification of vertebrata Division Agnatha (Lack jaw) Gnathostomata (Bear jaw) Super class Pisces (Bear fins) Class 1. Cyclostomata © 2022, Aakash BYJU'S. All rights reserved. Class 1. Chondrichthyes 2. Osteichthyes Tetrapoda (Bear limbs) Class 1. Amphibia 2. Reptilia 3. Aves 4. Mammals