Animal Kingdom Question 748
Assertion : Respiration in Amphioxus is done by gills and diffusion. Reason : Amphioxus is aquatic and possesses blood.
Options:
A) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C) If the assertion is true but the reason is false
D) If both the assertion and reason are false
Show Answer
Answer:
Correct Answer: A
Solution:
In Amphioxus, some exchange of and occurs between the water current and blood through the gill-clefts, but this appears doubtful since the blood contains no respiratory pigment.
The pharyngeal wall of Branchiostoma is richly vascular and the water current entering the pharyngeal cavity brings about the exchange of substances between the blood and the water.
It appears more probable that an exchange of gases occurs over the whole surface of the body and particularly in the walls of the atrium.
BETA
