Class 11 Biology - Chapter Animal Kingdom NCERT Solutions | Give the characteristic features of the

Welcome to the NCERT Solutions for Class 11th Biology - Chapter Animal Kingdom. This page offers a step-by-step solution to the specific question from Excercise 0 , Question 9: give the characteristic features of the following....
Question 9

Give the characteristic features of the following citing one example of each
a. Chondrichthyes and ostichthyes
b. Urochordata and cephalochordata

Answer

a. Chondricthyes: They have cartilaginous endoskeleton. Their gills are not covered by operculum. They are mainly marine and their body is streamlined. They are predaceous. Due to the absence of air bladder, they have to swim constantly to avoid sinking. Example: Trygon, Scoliodon, Pristis etc.

Osteicthyes: They have bony endoskeleton. They are both marine and fresh water fishes. Their body is streamlined. Gills are covered with operculum, skin is covered with cycloid/ ctenoid scales. Air bladder is present which regulates buoyancy. Example: Labeo rohita, Catla catla.

b. Urochordata and Cephalochordata: In Urochordata, the notochord is present only in larval tail and disappears in adults. Example: Salpa, Herdmania etc. In Cephalochordates, notochord extends from head or tip of the snout to tail region and persists throughout the life. Example: Brachiostoma.

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