Class Crustacea differ from Insecta in having:
two pairs of antennae
jointed foot
chitinous cuticle
none of these
Sigmoid notch is formed by :
cavity formed by humerus
cavity formed by radio ulna
cavity formed by tibia fibula
cavity formed by femur
B.
cavity formed by radio ulna
Radius and ulva are the bones of the fore-arm. Which are closely held together. The ulna is the long bone and bear a deep sigmoid notch for articulation with the trochlea of the humerus.
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