question_answer 19)

  Setae help in locomotion in earthworm but are not uniformly, present in all the segments. They are present in     (a) 1st segment                (b) last segment               (c) clitellar segment                  (d) 20th - 22nd segment

Answer:

                  (d) In earthworm, except for the 1st, last and clitellar segment, each segment bears a ringof tiny, curved, chitinous structures called setae.