Urochordata, Hemichordata and Cephalochordata are collectively known as
The chordate is a group or phylum in which there are the organisms which have the nerve cord or the spinal cord. There are three subphylums in this group known as the Hemichordate, Urochordate and the Cephalochordate. Acrania or Protochordata are lower chordates. They are all marine organisms. These are small and primitive chordates. They lack a head, skull or cranium. Thus, they are called as Acrania which means they do not have a body which have distinct head. They do not have a vertebral column, jaws and brain. The Acrania is divided into three subphyla as Hemichordata, Urochordata and Cephalochordata.
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.
Retrogressive metamorphosis is found in
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?
Which of the following animal is devoid of notochord and nerve cord in it's adult stage?