Assertion : Respiration in Amphioxus is done by both water and blood. Reason : Amphioxus is aquatic and possesses bloodA. If both the assertion and the reason are true and the reason is a correct explanation of the assertionB. If both the assertion and reason are true but the reason is not a correct explanation of the assertionC. If the assertion is true but the reason is falseD. If both the assertion and reason are false

Assertion : Respiration in Amphioxus is done by both water and blood.

1.	Assertion : Respiration in Amphioxus is done by both water and blood. Reason : Amphioxus is aquatic and possesses bloodA. If both the assertion and the reason are true and the reason is a correct explanation of the assertionB. If both the assertion and reason are true but the reason is not a correct explanation of the assertionC. If the assertion is true but the reason is falseD. If both the assertion and reason are false
Answer» Correct Answer - A In Amphioxus, some exchange of `O_(2)` and `CO_(2)` occurs between the water current and blood through the gillclefts, but this appears doubtful since the blood contains no respiratory pigment. The pharyngeal wall of Branchiostoma is richly vascular cavity brings `O_(2)`. The blood flows so close to the surface that some exchange of gases occurs over the whole surface of the body and particularly in the walls of atrium.