Retrogressive metamorphosis is found in
Metamorphosis is the phenomena in which there are changes which transform the organism form its juvenile stage to adult stage. In the case of retrogressive metamorphosis, the larva possesses the advanced features which get lost during the development. The adult is sedentary or degenerated with the primitive characters. The urochordate larva shows advanced chordate characters which get lost during metamorphosis. The tail present in the larvae for swimming gets lost. There is a loss of the rod-like notochord in the tail. There is a hollow nerve cord which forms the brain at the anterior end in case of the larvae. The hollow nerve cord in adults gets reduced to form a solid nerve ganglion.
Thus, 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.
Why the Amphioxus is considered as degenerated chordata?
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?