
Introduce the animal kingdom's diversity, contrasting animals with plants by features like no cell wall, heterotrophy, locomotion, nervous system, and notochord-based vertebrate classification.
Explore criteria for animal classification, focusing on germinal layers and body plans. Distinguish diplo plastic and triplo plastic groups and identify three body plans: cell aggregate, blind sac, and two-opening.
Explore the animal kingdom by classifying organisms into non-chordates and chordates, detailing phyla from Porifera and Cnidaria to Arthropoda and Mollusca, and tracing vertebrate evolution from jawless fish to mammals.
Explore phylum ctenophora or comb jellies, highlighting their radially symmetric bodies with outer ectoderm and inner endoderm, bioluminescence, retractable tentacles, and external fertilization.
Explore the phylum platyhelminthes, acoelomate flatworms with dorsoventrally flattened bodies, incomplete digestion, and parasitic tapeworms like Taenia and liver fluke, which bear hooks and suckers for attachment.
Explore Annelida with earthworm, leech, and Nereis, highlighting segmented bodies, true coelom, and closed circulatory systems. Note hermaphroditic earthworms and leeches, dioecious Nereis, and locomotion via circular and longitudinal muscles.
Explore the phylum Echinodermata through starfish and sea cucumber, highlighting pentamerous symmetry, tube feet, and calcareous spines, plus the water vascular system and external fertilization with indirect development.
Explore phylum Hemichordata, with balanoe glossies and sacko glossies as examples, noting a three-part body (proboscis, collar, trunk), burrowing lifestyle, gills, complete alimentary canal, and a closed colorless blood system.
Compare non-chordates and chordates, focusing on notochord absence, dorsal nerve cord, and ventral heart. Explore respiration structures and the presence of a post-anal tail, along with vertebrate subgroups.
Explore division Gnathostomata, jawed vertebrates, detailing fins and jaws, dermal scales, gill respiration, and a two-chambered heart, across the four classes Amphibia, Reptilia, Aves, and Mammalia.
Explore amphibians that live on land and in water, with moist mucus-covered skin, two pairs of limbs, gills in water, lungs on land, and a three-chambered heart.
Explore class Aves, highlighting flight adaptations such as wings and hollow bones, warm-blooded metabolism, and feathered, weight-reducing exoskeleton, with internal fertilization and hard-shelled eggs.
Explore the class reptilia, including lizards, snakes, and crocodiles, with dry scaly skin, limbs with claws, lungs, and three-chambered hearts (crocodiles and tortoises four-chambered); they lay eggs with internal fertilization.
Mammalia comprises mammals with mammary glands and warm-blooded, occupying terrestrial, aquatic, aerial, or arboreal habitats, with double circulation.
Description
The basic fundamental features such as level of organisation, symmetry, cell organisation, coelom, segmentation, notochord, etc., have enabled us to broadly classify the animal kingdom. Besides the fundamental features, there are many other distinctive characters which are specific for each phyla or class.
Porifera includes multicellular animals which exhibit cellular level of organisation and have characteristic flagellated choanocytes. The oelenterates have tentacles and bear cnidoblasts. They are mostly aquatic, sessile or free-floating. The ctenophores are marine animals with comb plates. The platyhelminths have flat body and exhibit bilateral symmetry. The parasitic forms show distinct suckers and hooks. Aschelminthes are seudocoelomates and include parasitic as well as non-parasitic roundworms.
Annelids are metamerically segmented animals with a true coelom. The arthropods are the most abundant group of animals characterised by the presence of jointed appendages. The molluscs have a soft body surrounded by an external calcareous shell. The body is covered with external skeleton made of chitin. The echinoderms possess a spiny skin. Their most distinctive feature is the presence of water vascular system. The hemichordates are a small group of worm-like marine animals. They have a cylindrical body with proboscis, collar and trunk.
Phylum Chordata includes animals which possess a notochord either throughout or during early embryonic life. Other common features observed in the chordates are the dorsal, hollow nerve cord and paired pharyngeal gill slits. Some of the vertebrates do not possess jaws (Agnatha) whereas most of them possess jaws (Gnathostomata). Agnatha is represented by the class, yclostomata. They are the most primitive chordates and are ectoparasites on fishes. Gnathostomata has two super classes, Pisces and Tetrapoda. Classes Chondrichthyes and Osteichthyes bear fins for locomotion and are grouped under Pisces. The Chondrichthyes are fishes with cartilaginous endoskeleton and are marine. Classes, Amphibia, Reptilia, Aves and Mammalia have two pairs of limbs and are thus grouped under Tetrapoda. The amphibians have adapted to live both on land and water. Reptiles are characterised by the presence of dry and cornified skin. Limbs are absent in snakes. Fishes, amphibians and reptiles are oikilothermous (cold-blooded). Aves are warm-blooded animals with feathers on their bodies and forelimbs modified into wings for flying. Hind limbs are adapted for walking, swimming, perching or clasping. The unique features of mammals are the presence of mammary glands and hairs on the skin. They commonly exhibit viviparity.
Course Content
Introduction
Criteria for Animal classification 1
Criteria for Animal classification 2
Animal Classification
Phylum Porifera
phylum platyhelminthes
Phylum Cnidaria
Phylum Ctenophora
Phylum Aschelminthes
Phylum Arthropoda
Phylum Mollusca
Phylum Echinodermata
Phylum Hemichordata
Non-chordates & Chordates
Division Gnathostomata
Chondrichthyes and Osteichthyes
Class Amphibia
Class Reptilia
Class Aves
Class Mammalia