The skin is a respiratory organ in ...........

In the lower order of invertebrate animals,how does the respiration process take place?

Which of the following respiratory organs are present in spiders and scorpions?

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 $p-q-r-s$.

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

Which of the following pairs correctly represent an animal and its respiratory organ?
$(a)$ Silverfish $-$ Trachea
$(b)$ Scorpion $-$ Book lungs
$(c)$ Sea squirt $-$ Pharyngeal gills
$(d)$ Dolphin $-$ Skin