Respiratory exchange in seeds occurs through

The waxy surface of the floating leaves of the hydrophytes prevents

If a fish is taken out of water,it dies immediately because...

Which of the following is not a character of a respiratory surface?

Given below are four matchings of an animal and its kind of respiratory organ:
$I.$ Silver fish - Trachea
$II.$ Scorpion - Book lung
$III.$ Sea squirt - Pharyngeal gills
$IV.$ Dolphin - Skin
The correct matchings are:

Skin of man cannot act as a respiratory organ because