In insects,oxygen is carried to different tissues by

In crustaceans,respiration occurs through ..........

$A$ frog must swallow air to expand the lungs because a frog:

Match the Column $I$ with Column $II$.

Column $I$ (Animals)	Column $II$ (Respiratory organs / surface)
$1$. Spider	$a$. Internal gills
$2$. Coelenterates	$b$. Book lungs
$3$. Frog	$c$. Plasma membrane
$4$. Fishes	$d$. Lungs
	$e$. External gills

Choose the correct option.

Choose the correct option by matching the organisms in Column-$I$ with their respective respiratory organs in Column-$II$.

Column-$I$	Column-$II$
$(p)$ Sponges	$(I)$ Through tracheal tubes
$(q)$ Insects	$(II)$ Through lungs
$(r)$ Molluscs	$(III)$ Vascularized gills
$(s)$ Reptiles	$(IV)$ Simple diffusion over their entire body surface
	$(V)$ By their moist cuticle

Find the correct sequence for $p-q-r-s$.

Explain the structures of respiratory organs for the exchange of gases in various groups/kingdoms of animals.