Who had the grandest impact on russia during the 20th century and why?

It would be Vladimir Lenin and the communist soviets. Because he laid the foundation of the Union Socialist of Soviet Russia or USSR and he is part of the ousting of the Tsar monarchy that reigned the country since the Medieval Period and also defeat the Democratic parties and the White Army during the Russian Civil War.

Apart of the parietal lobe

What the question i don't get it do u mean what she needs to do to auctually become one