Sunday, March 11, 2012

Comparison between chordates and non-chordates


Chordates
Non-chordates
1.        Notochord is present at least in some stage of life cycle
Notochord is absent
2.        Nerve cord is non-ganglionated, single, dorsal and hollow
Nerve cord is ganglionated, double ventral and solid
3.        Pharyngeal gill slits are present
Absent
4.        A post anal tail is present in some stages or throughout life
Post anal tail is absent
5.        Ventral heart is present
Dorsal heart is present
6.        Haemoglobin is present in RBC
Haemoglobin when present is in the blood plasma
7.        Endoskeleton and exoskeleton are present
Generally exoskeleton alone is present
8.        Hepatic portal system is present
Hepatic portal system absent
9.        Eyes are derived from brain
Eyes are derived from the skin
10.      Blood flow is forward in ventral vessel and backward in dorsal vessel
Blood flow is back ward in ventral vessel and forward in dorsal vessel


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