Bio Question

[dentalknight]

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Which of the following characterizes an open circulatory system?

a) five aortic arches are present
b) arteries branch into arterioles
c) blood is oxygenated at lungs
d) xylem carries water to where it is needed
e) blood flows from the dorsal vessel where it is collected

i wasnt sure what the answer is. anyone else know?

 

[PooyaH]

I'm thinking E but not 100% sure!

 

[DRHOYA]

I would say Choice E. My theory is this: Choice A is describing a system similar to Annelids, and thus they do not have open systems. Choice B is clearly wrong. Choice C is wrong b/c organisms with open circs usually don't have "true lungs"...although spiders have "book lungs". Choice D is clearly wrong for obvious reasons pertaining to the plant kingdom. Choice E is correct b/c in open circs, the aortic vessel acts as the pumping mechanism (and body movement) for these organisms. Hope that helps. 👍

 

[PooyaH]

Actually I think I'm a bit sure it's E, because in open circulatory systems you there's no true heart and blood vessels are used to pump blood. For closed circulatory systems, there should be a ventral vessel as well (like Annelids) So E is the only one that makes sense to me!

 

[doc3232]

I went with E because the others didn't show characteristics of an open circulatory.