Anmol Sharma is teaching live on Unacademy Plus
Class 11th 04. ANIMAL KINGDOM NEET/AIIMS ANMOL SHARMA
WHAT TO STUDY? Basis of Classification Levels of Organisation Symmetry .Diploblastic and Triploblastic Organisation (Germ Layer) . Coelom Segmentation Notochord . Classification of Animals . Phylum Porifera Phylum Colenterata Phylum Ctenophora . Phylum Platyhelminthes .Phylum Aschelminthes Phylum Annelida Phylum Arthropoda . Phylum Mollusca Phylum Echinodermata Phylum Hemichordata . Phylum Chordata
* Class Chonarichythyes * Class Amphibia . Class Aves Class Cyclostomata Class Osteichthyes Class Reptilia . Class Mammalia Key Point of Animal Kingdom
BASIS OF CLASSIFICATION Levels of Organisation . Cellular level - cells are arranged as loose cell aggregates. Some division of labour (activities) occur among the cells. e.g., Sponges. . Tissue level- the cells performing the same function are arranged into tissues. e.g., coelenterates. . Organ level - tissues are grouped together to form organs, each specialized for a particular function. e.g., Platyhelminthes, ascheminthes. level-snecaized for a particular . Organ system level - organs are associated to form functional systems, each system concerned with a specific physiological function. e.g., Annelids, Arthropods, Molluscs, Echinoderms and Chordates
Symmetry .Asymmetrical - any plane that passes through the centre does not divide body into equal halves. e.g., Sponges Radial symmetry - When any plane passing through the central axis of the body divides the organism into two identical halves. e.g Coelenterates, ctenophores and echinoderms (adults only) . bilateral symmetry - the body can be divided into identical left and right halves in only one plane. e.g., Annelids, Arthropods, Molluscs, Echinoderms (larvae) and Chordates.
Fig: (a) Radial symmetry (b) bilateral symmetry Source :- This image is from NCERT Textbook Page no. 47
Germ layers . Diploblastic - Animals in which the cells are arranged in two embryonic layers, an external ectoderm and an internal endoderm. An undifferentiated layer, mesoglea, is present in between the ectoderm and the endoderm. e.g Sponges, coelenterates.(NEET 2013) . Triploblastic - Animals in which the cells are arranged in three embryonic layers, an external ectoderm, an internal endoderm and middle mesoderm. e.g., Platyhelminthes, ascheminthes, Annelids, Arthropods, Molluscs, Echinoderms and Chordates.
Ectoderm Mesoglea Endoderm Mesoderm Fig (a) Diploblastic (b)Triploblastic Source :- This image is from NCERT Textbook Page no. 47
Coelom The body cavity, which is lined by mesoderm on both sides is called coelom . Acoelomates - animals in which the body cavity is absent. e.g., Sponges, coelenterates, platyhelminthes. Pseudocoelomates - In some animals, the body cavity is not lined by mesoderm, instead, the mesoderm is present as scattered pouches in between the ectoderm and endoderm. Such a body cavity is called pseudocoelom and the animals possessing them are called pseudocoelomates, e.g., aschelminthes Coelomates - Animals possessing coelom are called coelomates, e.g., annelids, molluscs, arthropods, echinoderms, hemichordates and chordates.
Coelom Pseudocoelom Fig Diagrammatic sectional view of: (a Coelomate (b) Pseudocoelomate (c) Acoelomate Source :- This image is from NCERT Textbook Page no. 48
Notochord Notochord is a mesodermally derived rod-like structure formed on the dorsal side during embryonic development in some animals. . Chordates - Animals with notochord in any stage of life. e.g., Fishes, Amphibians, Reptiles, Birds, Mammals etc. . Non chordates - Those animals which do not form this structure are called non-chordates, e.g., Porifera to echinoderms.
circulatory sysle is pmpe out of the heat t .open type - Blood is pumped out of the heart and the cells and tissues are directly bathed in it or closed type in which the blood is circulated through a series of vessels of varying diameters (arteries, veins and capillaries)