Which of the following have notochord throughout life?
Birds
Fish
Snake
Amphioxus
D.
Amphioxus
In chordates and sub- phylum Cephalochordates, notochord is present throughout life. In vertebrates, it is replaced by vertebral column.
Animals having a built in thermostat to maintain constant body temperature are known as
biothermic
poikilothermic
oligothermic
homeothermic
Which of the following cell type is capable of giving rise to other cell types in sponges?
Thesocytes
Pinacocytes
Cnidocytes
Archaeocytes