Notochords are found in
a. adult hemichordates (acorn worms).
b. adult urochordates (tunicates).
c. adult cephalochordates (lancelets).
d. a and b only.
e. b and c only.
C; Adult lancelets have notochords, as do larval tunicates. Adult tunicates lose the notochords during metamorphosis (choice b). Hemichordates do not have a notochord at any stage of their life cycle (choice a).
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A. uracil B. guanine C. cytosine D. adenine
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