1. Compare the movement of nematodes (vinegar eel) with that of annelid worms (earthworm)
relating these different kinds of movement to the arrangement of muscle layers in these animals.
Why might peristaltic motion be considered an advancement relative to sinusiodal movement?
2. using some easily observed traits, explain how to distinguish between these arthropods:
spiders, insects, millipedes, centipedes.
Solution
1.Nematodes move through their longitudinal muscles which causes pressure throughout their
body and it flexes instead of flattened and with the thrust it moves forward, In Case of
earthworms it uses two different set of muscles, circular muscles which runs on each segment
and longitudinal muscle which runs throughout the body. It uses the circular muscles first which
stretches the worm into longer and then it uses longitudinal muscles which it becames shorter
pulling the body forward.
2.Millipedes and centipedes (Myriapoda) have distingushed segmented bodies with a prominent
head and trunk. It has many pair of legs with a single pair of antennae and wings will be
generally absent. Spiders (Arachinida ) have a cephalothorax and an abdomen, four pair of legs
and wings and antennae which are generally absent. Finally the insects (Insecta) have a featured
head, thorax and abdomen with three pair of legs and a single pair of antennae, wings may be or
may not be present in some insect species..
1. Compare the movement of nematodes (vinegar eel) with that of anne.pdf
1. 1. Compare the movement of nematodes (vinegar eel) with that of annelid worms (earthworm)
relating these different kinds of movement to the arrangement of muscle layers in these animals.
Why might peristaltic motion be considered an advancement relative to sinusiodal movement?
2. using some easily observed traits, explain how to distinguish between these arthropods:
spiders, insects, millipedes, centipedes.
Solution
1.Nematodes move through their longitudinal muscles which causes pressure throughout their
body and it flexes instead of flattened and with the thrust it moves forward, In Case of
earthworms it uses two different set of muscles, circular muscles which runs on each segment
and longitudinal muscle which runs throughout the body. It uses the circular muscles first which
stretches the worm into longer and then it uses longitudinal muscles which it becames shorter
pulling the body forward.
2.Millipedes and centipedes (Myriapoda) have distingushed segmented bodies with a prominent
head and trunk. It has many pair of legs with a single pair of antennae and wings will be
generally absent. Spiders (Arachinida ) have a cephalothorax and an abdomen, four pair of legs
and wings and antennae which are generally absent. Finally the insects (Insecta) have a featured
head, thorax and abdomen with three pair of legs and a single pair of antennae, wings may be or
may not be present in some insect species.
