Biology · Biodiversity | Variety of Life

Wendell Meredith Stanley was the first to purify a virus, specifically the Tobacco Mosaic Virus (TMV) in 1935. He showed that TMV could be crystallized like a chemical and still remain infectious, which was a major breakthrough. This discovery helped prove that viruses were distinct from other microorganisms and opened the door to modern virology.

This option is incorrect, because his work allowed scientists to study "filterable agents" (what we now know as viruses), but he did not purify them. He laid the groundwork for virology but did not isolate or purify viruses himself.

This option is incorrect, because although he showed that the infectious agent could pass through Chamberland filters, implying it was smaller than bacteria, he did not purify the virus or understand its true nature—it was just called a "filterable virus" at that time.

This option is incorrect. He did not work on filterable agents or viruses specifically, though he suspected diseases smaller than bacteria might exist. He helped establish microbiology but not virology or virus purification.

This option is correct. Wendell Meredith Stanley was the first to purify a virus, specifically the Tobacco Mosaic Virus (TMV) in 1935. He showed that TMV could be crystallized like a chemical and still remain infectious, which was a major breakthrough. This discovery helped prove that viruses were distinct from other microorganisms and opened the door to modern virology.