Answer:
On earth, the genetic material of all the life form is made up of nucleic acid. So all the information about the organism is stored in the nucleic acid which is transmitted to the next generation.
There are two types of nucleic acid present in life forms on earth i.e., ribonucleic(RNA) acid and deoxyribonucleic acid(DNA). Most of the organisms contain DNA to store its genetic material and some forms contain RNA as their genetic material.
Therefore if an alien form of life is discovered on the mars then nucleic acid must be the following macro molecules would have to be discovered in this creature before scientists could suggest life on earth and life on mars have similar methods for storing and transmitting genetic information.