Q26. Which of the following statements are true for the phylum-Chordata?
a. In Urochordata notochord extends from head to tail and it is present throughout their life.
b. In Vertebrata 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.

4. (b) and (c)

Solution:
In chordates Central nervous system is dorsal and hollow.
Chordata is divided into 3 subphyla : Hemichordata, Tunicata and Cephalochordata.

Other characteristics:
Notochord present.
Pharynx perforated by gill slits.
Heart is ventral.
A post-anal part (tail) is present.

Q26.  Which of the following statements are true for the phylum-Chordata?
a. In Urochordata notochord extends from head to tail and it is present throughout their life.
b. In Vertebrata 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.