Animal kingdom class 11th | digital notes
Basis of classification
Despite of many dissimilarities organisms have some similarities such as given in box below..
Basis of Classification includes
- Levels of organisation
- Symmetry
- Diploblastic and Triploblastic Organisation
- Coelom
- Segmentation
- Notochord
levels of organistion cellular level, tissue level, organ level and organ
system level.
Circulatory system is open type or closed type.
symmetry
asymmetrical - plane through the center does not divide them into two equal
halves.
radial symmetry - When any plane passing through the center axis of the body
divides the organism into two equal halves.
bilateral symmetry - body can only divided into two equal halves in only one
plain ,exhibit bilateral symmetry.
Diploblastic and triploblastic organisation.
ectoderm + endoderm + mesoglea(undifferentiated layer) = diploblastic
ectoderm + endoderm + mesoderm = triploblastic(platyhelminthes to chordates)
Coelom
cavity between body wall and alimentary canal.
coelom should have both - the sides by mesoderm then it is to be a true cavity.
Exception - Ashelminthus (psudocoelom).
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