Given below are two statements. One is labelled Assertion (A) and the other is labelled Reason (R).  

Assertion (A) : Glomerular filtration is described as ultrafiltration.

Reason (R) : 1100-1200 ml of blood is filtered by the kidneys per minute.

In the light of the above statements, choose the most appropriate answer from the options given below.

Both (A) and (R) are true but (R) is not the correct explanation of (A).

Assertion (A): Glomerular filtration is indeed considered ultrafiltration due to the finely filtered process occurring across three layers: the endothelium of glomerular blood vessels, the epithelium of Bowman’s capsule, and a basement membrane between these two layers. This process selectively allows small molecules and ions to pass while retaining larger molecules such as proteins, resulting in the ultrafiltration of blood plasma.

Reason (R): The statement that 1100-1200 mL of blood is filtered per minute through the filtration membrane is true. This represents the glomerular filtration rate (GFR), which reflects the volume of blood filtered by the kidneys per minute.

While both Assertion (A) and Reason (R) are true, Reason (R) does not directly explain why glomerular filtration is considered ultrafiltration. The volume of blood filtered per minute mentioned in Reason (R) is related to the concept of GFR but does not address the specific mechanisms of ultrafiltration occurring across the glomerular membranes.