Why the Amphioxus is considered as degenerated chordata?
Amphioxus is called as degenerated Chordata because its excretory system contains protonephridia. The absence of heart and kidney, paired limbs or paired fins, a distinct head, distinct paired sense organs, gonads are without gonoducts.
So, the correct answer is option D.
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.
In which among the following animals, retrogressive metamorphosis is found?
Statement 1: Cephalochordata bears notochord throughout their life. Statement 2: In cephalochordates, notochord extends from head to tail.
Retrogressive metamorphosis is found in
Excretory organ of Herdmania is
The larval form of urochordates is called as
Sapla and Doliolum belongs to
Which of the following animal belongs to Urochordata?
Urochordata, Hemichordata and Cephalochordata are collectively known as
Which of the following animal is devoid of notochord and nerve cord in it's adult stage?