16. How is movement brought about in the following organisms?
a) Earthworm
b) Cockroach
Answers
Answer:
Earthworms move by alternate extension and contraction of the body using muscles. ... The body and legs of cockroaches have hard coverings forming an outer skeleton. The muscles of the breast connected with three pairs of legs and two pairs of wings help the cockroach to walk and fly.
Answer:
a) An earthworm moves using circular and longitudinal muscles, as well as bristles called setae. The earthworm can push the setae out of its body to grab the soil around it. To move forward, the worm uses its setae to anchor the front of its body and contracts the longitudinal muscles to shorten its body.
b) A cockroach moves its legs with the help of muscles near the limbs. It uses its breast muscles to move its wings and fly. A cockroach can walk, fly and even climb.