The current bicameral legislative structure isn't what was obtainable before independence and this picture gives an account of how much things have changed over the decades.
Nigeria Legislative Council in the 1940s
This is the interior part of the Nigeria Legislative Council in the 1940s. The 1st elections in Nigeria was held in 1923 to elect council members.
The 1922 Nigeria (Legislative Council) Order in Council provided for a 46-member Legislative Council, of which 23 were ex-officio officials, four were nominated officials, up to 15 were appointed unofficial members and four were elected.