how r vertebrataes divided into different divisions?

Asked by  | 29th Oct, 2008, 01:23: PM

Expert Answer:

Based on the difference in morphology and anatomy, vertebrates are grouped into 5 classes:

1. Pisces or fish have exoskeleton that means an outer skeleton of scales, endoskeleton or an internal support structure of bone/ cartilage. They breathe through gills. 

2. Amphibians have a slimy skin. Their larval forms respire through gills, while the adults have lungs for this purpose. 

3. Reptiles have an exoskeleton scales and they breathe through lungs.

4. Aves include birds. They have an exoskeleton of feathers and the forelimbs are modified to form wings for flight.

5. Mammalia includes organisms with an exoskeleton of hair and have external ears or pinna.                                                                                     

Answered by  | 6th Nov, 2008, 03:42: PM

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