Question

define auto catalytic & hetero catalytic nature of DNA ?

Answer 1

Autocatylitic reaction is a type of reaction in which one of the reactant is product of a reaction and reaction product itself is the catalyst for that reaction, then such catalysts are called autocatalyts and the reaction is said to have undergone autocatalysis, or reaction is autocatalytic in nature. Autocatalytic sets of reaction have the ability to replicate themselves.
DNA replication is an autocatalytic because reaction product (that is, DNA) is itself the catalyst of the reaction. One template DNA produces a new DNA molecule through replication..
Transcription is conversion of DNA into mRNA and then into proteins by translation. So it is heterocatalytic because DNA produces a different reaction product that is mRNA. 

Answer 2

Self‐replication is a fundamental concept. The idea of an entity that can repeatedly create more of itself has captured the imagination of many thinkers from von Neumann to Vonnegut. Beyond the sciences and science fiction, autocatalysis has found currency in economics and language theory, and has raised ethical fears memorably summed up by the “gray goo” trope. Autocatalysis is central to the propagation of life and intrinsic to many other biological processes. This includes the modern conception of evolution, which has radically altered humanity’s image of itself. Organisms can be thought of as imperfect self‐replicators which produce closely‐related species, allowing for selection and evolution. Hence, any consideration of self‐replication raises one of the most profound questions of all: what is life? Minimal self‐replicating systems have been studied with the aim of understanding the principles underlying living systems, allowing us to refine our concepts of biological fitness and chemical stability, self‐organization and emergence, and ultimately to discover how chemistry may become biology.