Question

Ralph is looking at a blood vessel under a microscope as part of his study about the cardiovascular system. He notices that the vessel contains blood and has valves. Determine the blood vessel being observed.

Answer 1

Vein because they have valves to prevent back flow of blood.

Answer 2

I think the correct answer for this would be the veins. Ralph is observing a vein since he notices that the vessel contains blood and which is the function of the veins - to carry blood around the body. Hope this answers the question. Have a nice day.