Short answers, pulled from the story.
Tsar Nicholas II established the first elected parliament in 1905 following violent upheaval during the Russian Revolution of that year. Two early attempts by the Tsar to activate the body failed completely and each initial assembly dissolved after only a few months of operation.
Boris Yeltsin introduced a new Constitution following the 1993 Russian constitutional crisis which transformed the Russian Federation into a federal semi-presidential republic. The nationwide referendum approved this Charter creating a bicameral parliament composed of the State Duma and the Federation Council.
The legislature's term length started at two years during the 1993, 1995 election period before shifting to four years for the 1999, 2007 elections period. Since the 2011 elections, the term length has been set at five years.
After the 2003 elections a dominant-party system emerged with United Russia dominating the State Duma. All subsequent elections saw United Russia receive an absolute majority of seats exceeding 226.
Any citizen aged 21 or older with election rights may be elected as a deputy in the State Duma. That same person cannot serve simultaneously in the Federation Council or hold office in any other representative body of state power.