Q. Which is incorrect ? (C.B.S.E.2006) (Solved)
1. Presence of nonrespiratory air sacs increases efficinency of respiration in birds
2. In insects,circulation body fluids serve to distribute oxygen to tissues
3. Principle of counter - current flow facilitates efficient respiration in gills of fishes
4. Residual air in lungs slightly decreases the efficiency of respiration in mammals
- b. In insects,circulation body fluids serve to distribute oxygen to tissues