Class Crustacea differ from Insecta in having:
two pairs of antennae
jointed foot
chitinous cuticle
none of these
Which of the following character is presence essentialy in chordates ?
Ventral spinal chord
Dorsal heart
Pharyngeal gill slits
Blood flow in forward direction in ventral blood vessels
Which insect is useful for us ?
Periplaneta
Musca
Bombyx
Mosquitoes
C.
Bombyx
Bombay mori is a silk producing insect which is reared on mulberry leaves for commercial production of silk. Whereas Mosquito, Musca and Periplanata are harmful Arthropodes.
Which of the following is not found in Hydra ?
Epithelio-muscular cells
Cnidocyte
Choanocyte
Nerve cells
Which of the following symmetry is found in adult sea-anemone ?
Radial
Biradial
Bilateral
Spherical
Pearl oyster is a mollusc which belongs to class :
Cephalopoda
Pelecypoda
Scaphopoda
Gastropoda