GENERAL HISTOLOGY

Detailed explanation-1: -The renal artery carries oxygenated blood whereas the renal vein carries deoxygenated blood. Since the blood that contains excretory products is from other organs to the kidney via the renal artery, the renal artery has more urea than the renal vein.

Detailed explanation-2: -Renal artery carries blood to the kidney whereas the renal vein carries blood away from the kidney. As the kidney filters the blood, renal vein which carries blood away has less urea concentration than the renal artery.

Detailed explanation-3: -The kidney receives the oxygenated blood through the renal artery. The kidney transports the deoxygenated blood through the renal vein. Since the renal vein carries deoxygenated blood, Carbon dioxide is present in a lower concentration in the renal artery than in the renal vein.

Detailed explanation-4: -Option D Dorsal aorta/renal artery: The renal artery transports oxygenated blood to the kidney. Inside the kidney it branches off into smaller arteries to supply blood to the interior parts of the organ. Since they carry pure blood, they do not contain any urea.

Detailed explanation-5: -Blood with a lot of nitrogenous waste enters the kidney through renal artery. This blood after filteration leaves the kidney through renal vein. So, the blood in renal vein has less nitrogenous waste than the blood in renal artery.