A molecule that can act as the genetic material must fulfill all the mentioned criteria except one which is incorrect.

It should not provide the scope for slow changes (mutation) that are required for evolution.

The correct answer is Option (3) → It should not provide the scope for slow changes (mutation) that are required for evolution. 

It should be able to generate its replica: This is true. Genetic material must be able to replicate itself accurately so that it can be passed on to subsequent generations. This is a fundamental characteristic of DNA, RNA, and other genetic molecules.

It should be able to express itself in the form of "Mendelian character": This is true. Genetic material carries the information necessary for the expression of traits, including those that follow Mendelian principles of inheritance. Mendelian characters are traits that are controlled by single genes and exhibit predictable patterns of inheritance, which is facilitated by the presence of genetic material.

It shouldn't provide the scope for slow changes(mutation) that are required for evolution: This is false. Genetic material must allow for variations and mutations over time to drive evolutionary processes. This variation provides the raw material for natural selection to act upon, leading to adaptation and evolution of species.

It should be stable chemically and structurally : This statement is true. Genetic material should be chemically and structurally stable to ensure accurate replication and transmission of genetic information. While genetic material can undergo changes (mutations) over time, these changes are typically not due to inherent instability of the molecule itself, but rather external factors such as mutagens or replication errors.