Solution:1. The concept of basic structure was laid down by the Supreme Court in the Keshavanand Bharti Case (1973). The basic structure doctrine states that the Constitution of India has certain basic features that cannot be altered or destroyed through amendments by the Parliament. Article 368 does not give absolute powers to the Parliament to amend any part of the Constitution. Thus, statement (1) is correct.
2. The amendment in basic structure can also not be brought via Constituent Assembly since it was dissolved in 24th January, 1950. Hence, statement (2)is incorrect.
3. Constituent power is the power to formulate a Constitution or to propose amendments to or revisions of the Constitution and to ratify such proposal. The Constitution of India vests constituent power upon the Parliament subject to the special procedure laid down therein. However, scope to amend the basic structure is limited. Hence, statement (3) is incorrect.