Considering the age of the various segments of an annelid such as an earthworm,

a. They are born with all segments present and these merely grow in size; this allows segment count to be a major feature in their identification
b. New segments are added just behind the prostomium, so the oldest segments are at the posterior end
c. New segments are added just in front of the pygidium, so the oldest segments are at the anterior end
d. Each segment doubles several times in life so all of the segments are half or one-fourth "new" at any one time
e. Segments grow and duplicate in a haphazard fashion preventing their use in identification


Answer: c. New segments are added just in front of the pygidium, so the oldest segments are at the anterior end

Biology & Microbiology

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