In which of the following, notochord is present in embryonic stage? (a) All chordates (b) Some chordates (c) Vertebrates (d) Non chordates
Option A Chordates are the animals that have notochord, a skeletal rod present at some stage in life cycle. In lower vertebrates, notochord persists throughout life while in higher vertebrates it is replaced by vertebral column in adults. Nonchordates never develop notochord, not even in embryonic stage.
