Which of the following possesses a non-ganglionated nerve cord?

"All vertebrates are chordates but all chordates are not vertebrates". Justify the statement.

Which of the following statements are true for the phylum $Chordata$?
$(a)$ In $Urochordata$,the notochord extends from head to tail and is present throughout their life.
$(b)$ In $Vertebrata$,the notochord is present during the embryonic period only.
$(c)$ The central nervous system is dorsal and hollow.
$(d)$ $Chordata$ is divided into $3$ subphyla: $Hemichordata$,$Tunicata$,and $Cephalochordata$.

What is the phylum of the frog?

All chordates have the following characteristics:

Which of the following possesses an endoskeleton made of cartilage or bone?