Short answers, pulled from the story.
Lysenkoism was a pseudoscientific political campaign led by Soviet biologist Trofim Lysenko that rejected Mendelian genetics and natural selection in favor of a form of Lamarckism. It was dangerous because it had state backing: more than 3,000 biologists were dismissed or imprisoned, numerous scientists were executed, and genetics research in the Soviet Union was effectively destroyed for a generation.
Trofim Lysenko was a Soviet agronomist from a peasant family who claimed in 1928 to have developed techniques that could radically increase crop yields. He gained power through support from the Communist Party and from Joseph Stalin personally, who stood and applauded Lysenko in 1935 after Lysenko compared his scientific critics to enemies of Soviet collectivization.
Nikolai Vavilov, the president of the Soviet Agriculture Academy and Lysenko's former mentor, was arrested in 1940 after publicly denouncing Lysenko and died in prison in 1943. He was among the most prominent scientists destroyed by the campaign.
Lysenkoism was declared the only correct theory at the end of a week-long session of the Academy of Agricultural Sciences held from the 31st of July to the 7th of August 1948. The session was organized by Lysenko and approved by Stalin, after which the Ministry of Higher Education ordered all biological institutes to purge non-conforming scientists.
Poland, Czechoslovakia, East Germany, China, and North Vietnam all adopted Lysenkoism to varying degrees. China banned open discussion of Mendelian genetics from 1949 until 1956, and the lingering Lysenkoist influence in China contributed to agricultural yield losses connected to the Great Famine.
No. Heritable epigenetic effects have been found, but they are minor and unstable compared to conventional genetic inheritance. Lysenko held that environment-induced changes are the primary mechanism of all heritability, which epigenetics does not support. The geneticist Lev Zhivotovsky's claim that Lysenko helped found modern developmental biology is described in the scientific literature as unsupported.