Question 47
Give examples for the following
(a) Bilateral, dorsiventral symmetry is found in
(b) Worms causing disease elephantiasis is
(c) Open circulatory system is found in
(d)
(a) Liver fluke - It belongs to the phylum Platyhelminthes in which body is flattened dorsiventrally and with bilateral symmetry
(b) Filarial worm - It belongs to phylum nematodes. These are very familiar as parasitic worms causing diseases, elephantiasis
(c) Arthropods - In phylum arthropods, circulatory system in which blood does not flow in well-defined blood vessels and the coelomic cavity is filled with blood is called open type of circulatory system
(d) Nematodes - In nematodes pseudocoelom is a fluid-filled body cavity lying inside the external body wall of the nematode that bathes the internal organs, including the alimentary system and the reproductive system