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