The excretory material of bony fish is:

• urea

• protein

• ammonia

• amino acid

252.

Food storage in Leucosolenia occur by :

• ostia

• osculum

• thesocyte

• spongocoel

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

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

Body cavity of adult Ascaris is :

• haemocoel

• amphicoel

• pseudocoel

• schizocoel

All worms are :

• triploblastic

• segmented

• endo-parasites

• free - living

Pearl oyster is a mollusc which belongs to class :

• Cephalopoda

• Pelecypoda

• Scaphopoda

• Gastropoda