Body Fluids and Circulation — BIOLOGY STD 11 Science — Question
Gujarat BoardEnglish MediumSTD 11 ScienceBIOLOGYBody Fluids and Circulation3 Marks
Question
Why renal portal system is absent in mammals?
✓
Answer
The mammals have no renal portal system due to the following facts:
It is an evolutionary trend that fishes and amphibians have well-developed renal portal system, while, in reptiles and birds this system gets reduced. Finally in mammals it ultimately disappears.
The heart of mammals is four-chambered, due to which there is a total separation of oxygenated and deoxygenated blood.
Posterior portion of the body gets oxygenated blood from the heart and after oxidation process, etc., the blood does not contain so much impurities that it should go to the kidneys for filtration.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.