Viruses are the particles of _.

Explanation

Viruses are acellular entities composed of genetic material, which can be either DNA or RNA but never both. This genetic material is enclosed within a protein coat called a capsid, which protects the nucleic acid and aids in infection. Together, the nucleic acid and the capsid form the nucleocapsid. In many viruses, an additional outer envelope derived from the host cell membrane surrounds the capsid; this envelope contains lipids as well as viral proteins (such as glycoprotein spikes) that help the virus attach to and enter host cells.