The common names for $Fasciola \ hepatica$ and $Taenia \ solium$ are:

Give the differences between bony and cartilaginous fish.

State the reason for the following:
$(i)$ Nematodes have a pseudocoelom.
$(ii)$ Arthropods have an open circulatory system.
$(iii)$ Echinoderms are named as such.

$(a)$ Associate any three phyla of Animalia with triploblastic body organisation and bilateral symmetry.
$(b)$ State the meaning of triploblastic body organisation and bilateral symmetry.
$(c)$ On the basis of presence or absence of coelom,compare the three phyla answered in $(a)$.

Justify giving one reason: crocodiles have a four-chambered heart,but are still classified as reptiles.

Hard calcium carbonate structures are used as a skeleton by