Discuss the 42nd Constitutional Amendment Act of the Indian Constitution.

42nd Constitutional Amendment Act, 1976 ("Mini-Constitution"):

Enacted during the Internal Emergency based on the Swaran Singh Committee recommendations, it introduced the most comprehensive structural revisions in the Constitution:

• Preamble: Added three new words — "Socialist", "Secular", and "Integrity".
• Fundamental Duties (Part IV-A): Inserted Article 51A prescribing 10 Fundamental Duties for citizens.
• New DPSPs (Part IV): Added Article 39A (Free legal aid), Article 43A (Workers' participation in management), and Article 48A (Protection of forests and wildlife).
• Concurrent List Expansion: Transferred 5 subjects from State List to Concurrent List (Education, Forests, Weights & Measures, Protection of wild animals/birds, Administration of justice).
• Cabinet Advice: Made the advice of the Union Cabinet explicitly binding on the President (Art. 74).
• Judicial & Parliamentary Changes: Extended Lok Sabha/Assembly tenure to 6 years (later restored to 5 years by the 44th Amendment, 1978).