Final answer:
True, all viruses have a nucleic acid genome and a protective capsid made of proteins, which are fundamental components of their structure.
Step-by-step explanation:
The statement 'All viruses are composed of nucleic acid and protein' is true. Viruses are acellular entities that consist of a nucleic acid genome (either DNA or RNA, but never both) enclosed within a protein coat known as a capsid. The capsid is composed of protein subunits called capsomeres. While some viruses may also have an outer envelope derived from host cell membranes, this is not a component of all viruses. Therefore, while the overall structures can be quite varied and complex, the fundamental components of all viruses are the nucleic acids and proteins that form the capsid.