What was the significance of the Constitution (Twenty-seventh Amendment) Act, 1971, and its impact on s. 4?
The Constitution (Twenty-seventh Amendment) Act, 1971, had the significant impact of amending Section 4 by substituting "Union territory of Goa, Daman and Diu or Pondicherry" with a different term. This change occurred on February 15, 1972, as stated in the context provided.