The characteristic of injecting DNA or RNA into the nucleus of a (host) cell corresponds to viruses.
Explanation:
Viruses are not considered living beings, since they are only made up of genetic material covered by a viral capsid and cannot fulfill the functions of a cell. For this reason viruses need to introduce their genetic material into a host cell, to transcribe its genetic code and achieve replication.
Due to their mechanism of reproduction, viruses are biological agents capable of producing disease by altering the conditions of the organisms they use as hosts.
