Question

In Amphioxus, circulatory system is

• A. Closed
• B. Without heart
• C. Without respiratory pigment
• D. All of the above

Answer 1

The correct option is D All of the above

A) Closed circulatory system is the one in which blood circulates in body in closed tubes called blood vessels.

B) The heart is absent in amphioxus but blood is pumped by contractile vessels.

C) Dissolved oxygen in the blood by diffusion is sufficient to carry out vital activities and hence, there is no respiratory pigment.

Since all these features are present in amphioxus.

So, the answer is 'All of the above'.