Question

which of the following have notochord throughout life. a.amphioxus. b.snake. c.fish. d.bird.

Answer 1

amphioxus is the right answer

Answer 2

"Amphioxus have notochord" throughout life.  

Answer: Option a

Explanation:

Notochord is a "rod-like structure" formed on dorsal side which means upperside during the embryonic development in certain animals. It is derived from the mesoderm cells. All "animals with notochord" are called as Chordates.

In some chordates namely, snakes, fish and bird, the notochord is replaced by vertebral column whereas in case of amphioxus, it is present throughout the life period.