Identify a member of the phylum Porifera.

Explain by giving three reasons,how the work done by earlier scientists with respect to classification is helpful to the present generation.

Who introduced the system of scientific nomenclature of organisms?

Name the five classes of vertebrates. Compare any two on the basis of their $(i)$ Habitat,$(ii)$ Covering of skin,$(iii)$ Respiratory organs,$(iv)$ Chambers of heart,and $(v)$ Reproduction.

Name the phylum to which Leech and Earthworm belong.

Sehai and Sidak observed an animal in their garden. Sehai called it an insect while Sidak said it was an earthworm. Choose the character from the following which confirms that it is an insect.