The respiratory organ of insects is.......

Match the following columns:

Column-$I$ (Plant Part)	Column-$II$ (Gas Exchange Structure)
$P$. Leaves and young stems	$I$. Lenticels
$Q$. Woody stems	$II$. Stomata
$R$. Roots	$III$. Root hairs

In which of the following is the skin an accessory respiratory organ?

Among vertebrates,...$A$... use gills whereas reptiles,birds and mammals respire through the ...$B$... Amphibians like frogs can respire through ...$C$... also. Mammals have a well adapted respiratory system. Select appropriate choice for the blanks $A, B$ and $C$ to complete the given $NCERT$ statement.

The spiracle participates in which of the following processes?

Match the following columns:

Column-$I$ (Invertebrates)	Column-$II$ (Respiratory Organs)
$P$. Sponges,Coelenterates,Flatworms	$I$. Gills
$Q$. Earthworms	$II$. Simple diffusion through body surface
$R$. Insects	$III$. Vascularized bags (Lungs)
$S$. Aquatic arthropods and molluscs	$IV$. Tracheal tubes
$T$. Terrestrial arthropods and molluscs	$V$. Moist cuticle