Answer:
The correct option is C: antigen-binding sites
Explanation:
The antibody is shaped much like the letter Y in the English alphabet. It has two antigen binding sites that are identical in nature. The specificity of these sites is determined by the amino acid sequence that makes it up. Antibodies are complementary to these antigen binding sites, and the antibodies have an incredible ability to recognize a great variety of antigens.
Hope that answers the question, have a great day!
I believe, for the artery, they have, an open, circular lumen an a thick media
Veins on the other hand, have somewhat collapsed lumen and a thinner media. Arteries are blood vessels that carry blood out of the heart to other parts of the body, all arteries carry oxygenated blood except the pulmonary artery which carries deoxygenated blood from the heart to the lungs. Veins carry blood from other body parts to the heart, all veins carry deoxygenated blood except the pulmonary vein which caries oxygenated blood from the lungs to the heart.