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Explain each of the following: (i) The tracheoles lack spiral bands of chitin; (ii) The floor of the mouth is lowered during inhalation in a bony fish.

Explain each of the following: (i) The tracheoles lack spiral bands of chitin; (ii) The floor of the mouth is lowered during inhalation in a bony fish.

Answers


John
(i) To reduce the thickness of the epithelial lining making tracheoles permeable to respiratory gases reduces the distance to be covered by respiratory gases increasing rate of diffusion.

(ii) For efficient gases exchange muscular contraction of the floor of the mouth increases the volume and decrease the pressure in the mouth cavity forcing water to rush into mouth
johnmulu answered the question on May 4, 2017 at 05:58

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