Read the assertion and reason carefully to mark the correct option in question.
Assertion: The epithelial cells of Bowman's capsule called podocytes are arranged in an intricate manner so as to leave some minutes spaces called filtration slits or slit pores.
Reason: Ultra filtration is the first step of urine formation.
If both assertion and reason are true but reason is not the correct explanation of the assertion.
Assertion-Reason relation
Glomerulus is a tuft of capillaries formed by the branching of afferent arteriole. It is housed inside the Bowman’s capsule. The podocytes (epithelial cells) of Bowman’s capsule are arranged such that minute pores are formed in the membrane, called slit pores or filtration slits.
The slit pores are so small that almost all the constituents of the plasma except the proteins pass into filtrate which gets collected in the lumen of the Bowman’s capsule. This helps in ultra filtration of blood.
Hence, the assertion statement is correct.
Urine formation involves three processes - ultra filtration, reabsorption and secretion. Ultra filtration refers to the process of filtering of blood through minute pores under high pressure. It is the first step in urine formation which is carried out in three layers (endothelium of glomerular blood vessels, epithelium of Bowman’s capsule and the basement membrane between the two layers).
Hence, the reason statement is correct. However, the reason is not the correct explanation of the assertion.
Final Answer:
(B) If both assertion and reason are true but reason is not the correct explanation of the assertion.