Explanation

The first constitution of Pakistan was abrogated by Ayub Khan.

From 1947 to 1973, the country had a unicameral legislature.

1. The 1956 Constitution established a unicameral Parliament with legislative powers.
2. The 1962 Constitution introduced a federal state with a presidential form of government.
3. The 1973 Constitution adopted a bicameral system at the center, called "The Parliament," comprising the President, the National Assembly, and the Senate.