ii.What are the structures found on the ventral side of each segment of the earthworm that help in locomotion? [1 m]
iii.Name the two sets of muscles involved in the movement of an earthworm. [2 m]
(b) Diagram 2.1 shows locomotion in an earthworm
i. What happen to its body when the outer layer of muscles contract? [1 m]
ii. What happen to its body when the inner layer of muscles contract? [1m]
iii.Explain what happen at E. [3 m]
(c)i. State the type of skeleton in an insect. [ 1m]
ii. Explain the role of the long and powerful hind legs of a grasshopper during jumping. [ 2m ]
Suggested Answer:
(a) (i) Hydrostatic skeleton
(ii)Chaetae / bristles
(iii) P1 - Circular muscle
P2 - Longitudinal muscle
(b) i. Becomes longer / extended / segments become longer/ thinner and lengthened
ii. Segments bulge / shorten /thicker
iii. P1 - Circular muscles contract / outer layer contract
P2 - Longitudinal muscles relax / inner layer relax
P3 - Chaetae retracted / secure segment in the anterior to the ground.
P4- the body become thinner and lengthened
P5- its body will be extended forward
(c)i. Exoskeleton
ii. P1 - Flexor muscle in each femur contracts bringing the
tibia closer to the femur, into a Z position;
P2 - then, extensor muscles contract and propels the
grasshopper into the air
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