Final Answer:
Viruses are fundamentally a nucleic acid core surrounded by a protein coat or capsid. The viral genome comprises either DNA or RNA, carrying the genetic instructions essential for viral replication within a protective protein coat or capsid.
Step-by-step explanation:
Viruses are fundamentally a nucleic acid core surrounded by a protein coat or capsid. The nucleic acid core can be either DNA or RNA, containing the genetic instructions for viral replication.
The capsid provides protection to the viral genetic material and facilitates its entry into host cells. In some viruses, an additional lipid envelope derived from the host cell membrane surrounds the capsid. This envelope often contains viral glycoproteins that play a crucial role in the virus's ability to attach to and enter host cells.
The combination of the nucleic acid core and the protein coat or envelope constitutes the basic structure of a virus, allowing it to hijack host cellular machinery for replication.