Question

One Short revision of animal kingdom

According to the NCERT...

Answer 1

Answer:

Animal kingdom comprises of multicellular eukaryotic animals and is one of the kingdoms among five kingdom scheme of classification (by Whittaker).

Classification of animal kingdom is based on different important characteristic features like habitat, level of organization, symmetry etc.

(i) Characters of Non Chordata (Invertebrates): The animals which lack a notochord are called invertebrates. e.g. Amoeba, sponges, Hydra, worms, insects, etc., Invertebrates are characterised by the following salient features –

(1) The vertebral column is absent.

(2) the nerve cord is solid in nature.

(3) The nerve cord is present on the ventral side and never on the dorsal side.

(4) When alimentary canal is present, it lies dorsal to the nerve cord.

(5) Invertebrates may be acoelomate or pseudocoelomate or true coelomate.

(6) They have either asymmetry or radial symmetry or bilateral symmetry.

(7) The circulatory system is open type or closed type.

(8) They exhibit all possible type of reproduction.