Do viruses possess a capsid?

Viruses are indeed classified as having a capsid, which is a protein shell that encloses their genetic material. The capsid serves several essential functions: it protects the viral genome from degradation by enzymes and facilitates the delivery of the viral nucleic acid into host cells during infection. The structure of the capsid can vary among different viruses, but it is a fundamental feature of all viruses.

Regarding the other options, some might suggest that not all viruses have a capsid; however, even those that appear to lack a traditional capsid (like some complex viruses) will still have structural proteins surrounding their nucleic acid. Therefore, it’s accurate to say that viruses do possess a capsid as a defining characteristic of their structure.