The excretory material of bony fish is:
urea
protein
ammonia
amino acid
A.
urea
The excretory and osmoregulatory organs of the fishes are the gills and kidney. Excretion in bony fishes is ureotelic (i.e., they excrete urea) but some freshwater bony fishes are ammonotelic (i.e., excrete ammonia).
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 of the following is not found in Hydra ?
Epithelio-muscular cells
Cnidocyte
Choanocyte
Nerve cells
Class Crustacea differ from Insecta in having:
two pairs of antennae
jointed foot
chitinous cuticle
none of these
