Class Crustacea differs from lnsecta in having
two pairs of antennae
jointed foot
chitinous cuticle
none of the above
Which of the following character is present essentialy in chordates
Ventral spinal chord
Dorsal heart
Pharyngeal gill slits
Blood flow in forward direction in ventral blood vessels
C.
Pharyngeal gill slits
Chordate animals, at some time in their life history, exhibit the following three diagnostic
charcters :
(1) Presence of notochord.
(2) Presence of dorsal tubular nerve cord.
(3) Presence of gill clefts during development.
Beside these, some other characters are :
(4) Ventral heart.
(5) Hepatic portal system.
In contrast to annelids the platyhelminthes show
radial symmetry
presence of pseudocoel
bilateral symmetry
absence of body cavity