Question

Explain how animals in vertebrata are classified into further subgroups.

Answer 1

• Vertebrata can be further classified into sub groups on the basis of simple to complex body structures and their functions. 
• For example, fishes have two chambered hearts, amphibians have three chambered hearts while in birds and mammals have four chambered hearts to keep the oxygenated and deoxygenated blood separate. 
• The following characteristic features are considered for classifying vertebrate into the further sub groups.

Class pisces: Characteristics:	Exoskeleton of scale, endoskeleton of bone, cartilage, breaths through gills.
Class Amphibia	Gills in larva, lungs in most adults, slimyskin.
Class Reptilia	Exoskeleton of scales, laying eggs on land only.
Class Aves	Exoskeleton of feathers, lay eggs outside water, flight possible.
Class Mammals	Exoskeleton of hair, external ears, mostly giving birth to live young ones.