Which scientist is associated with the discovery that fibrinogen is a plasma protein converted to fibrin in coagulation?

• A. William Hewson
• B. Louis Pasteur
• C. Joseph Lister
• D. Marcello Malpighi

Answer: (A)

The concept being tested is the identification of the scientist who first linked fibrinogen as a soluble plasma protein that is converted into fibrin during clot formation. William Hewson showed that blood plasma contains a soluble substance that, when the coagulation process occurs, is transformed into fibrin to form the clot. This work established fibrinogen as the precursor to fibrin and laid the groundwork for understanding how the clot is built from plasma proteins. In modern terms, thrombin acts on fibrinogen to produce fibrin strands that stabilize the clot. The other scientists listed made important contributions in different areas—Pasteur in microbiology and germ theory, Lister in antiseptic technique, and Malpighi in anatomy and microscopy—so Hewson is the one associated with this specific discovery.