Which of the following statements are true for the phylum Chordata? Statements: (a) In Urochordata notochord extends from head to tail and it is present throughout their life. (b) In Vertebrates notochord is present during the embryonic period only. (c) Central nervous system is dorsal and hollow. (d) Chordata is divided into 3 subphyla: Hemichordata, Tunicata and Cephalochordata. Choose the correct option from those given below.
Answer: (B) (b) and (c). Statement (b) is true: in Vertebrata the notochord is present only during the embryonic period and is later replaced by the vertebral column.
- A.(a) and (b)
- B.(b) and (c)✓
- C.(d) and (c)
- D.(c) and (a)
Correct Answer
(B) (b) and (c)
Solution & Explanation
Statement (b) is true: in Vertebrata the notochord is present only during the embryonic period and is later replaced by the vertebral column. Statement (c) is true: chordates have a dorsal, hollow nerve cord. Statement (a) is wrong because in Urochordata the notochord is confined to the larval tail (it is Cephalochordata where it extends head to tail throughout life), and (d) is wrong because the three subphyla are Urochordata, Cephalochordata and Vertebrata, with Hemichordata now placed as a separate non-chordate phylum. Hence option B. NCERT Reference: Page 46, line 27