Question

Choose the correct answer from the alternatives given.
A part of the circulatory system which plays an important role in fish but does not occur in higher land animals is:

• A. renal portal system
• B. hepatic portal system
• C. renal arteries
• D. hepatic arteries

Answer 1

The correct option is A renal portal system

Renal portal system is well developed in fishes and amphibians, it is reduced in reptiles and birds and is absent in mammals. This system carries blood from the posterior region of the body to the kidneys by renal portal veins, hence its name. The kidneys remove the waste products from the blood and then the blood is passed to the post caval by renal veins. The mammals have no renal portal system because the heart of mammals is four-chambered. Due to the four-chambered heart in mammals, there is a total separation of oxygenated and deoxygenated blood.

So, the correct option is 'Renal portal system'.