Class Crustacea differs from lnsecta in having
two pairs of antennae
jointed foot
chitinous cuticle
none of the above
A.
two pairs of antennae
The main characteristics of class Crustacea and Insecta are as follows :
(1) Class Crustacea : Mostly aquatic with gills, two pairs of antennae and at least three pairs of jaws, appendages mostly biramous and always more than four in the trunk region. Example : prawn, crab, lobster etc.
(2) Class Insecta : Hexapod arthropods with a pair of antennae and three pairs of Jaws. Example : cockroach, grasshopper, bees,housefly etc.
Sigmoid notch is formed by
cavity formed by humerus
cavity formed by radius-ulna
cavity formed by tibia-fibula
cavity formed by femur
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
If dorsal nerve of spinal cord is broken down then its effect is
no impulse is transmitted
impulse is transmitted but slowly
impulse is transmitted fast
no effect on impulse
