Short answers, pulled from the story.
The Academy of Sciences of the Soviet Union operated from 1925 to 1991, formed by a resolution of the Central Executive Committee and the Council of People's Commissars on the 27th of July 1925. It was replaced by the Russian Academy of Sciences after the Soviet Union's collapse.
Alexander Karpinsky, a geologist who had previously led the Russian Academy of Sciences, was the first president of the Academy of Sciences of the Soviet Union, serving until 1936.
The academy's Presidium and fourteen scientific institutes were transferred from Leningrad to Moscow in 1934, under a decree signed by Vyacheslav Molotov on the 25th of April 1934. The historian Felix Perchenok described the move as one of the most important steps toward making the academy the headquarters of Soviet science.
The Academic Case was a wave of arrests between December 1929 and December 1930 in which more than 100 people connected to the Academy of Sciences of the Soviet Union were detained, mostly humanities specialists and historians.
By 1985, the Academy of Sciences of the Soviet Union had 274 full members, 542 corresponding members, about 330 scientific institutions, and 57,000 scientists and researchers among 217,000 total employees.
The Russian Academy of Sciences replaced it, created by a presidential decree on the 21st of November 1991. All members of the Academy of Sciences of the Soviet Union, including those in the newly formed Commonwealth of Independent States, automatically became members of the new body.