Final answer:
Virus making instructions are coded in the virus core's genome, which can be either DNA or RNA, encased in a protein capsid made up of capsomeres.
Step-by-step explanation:
The instructions for making a virus are coded in the virus core, which contains the genome or total genetic content of the virus. This genome may consist of DNA or RNA, and it is encapsulated within a protective protein shell known as a capsid. The capsid is composed of smaller protein subunits called capsomeres.
There are various types of viral genomes, such as single-stranded or double-stranded, linear or circular, and these contain only the necessary genes for protein coding that the virus is unable to obtain from the host cell. Furthermore, some viruses have additional structures like an envelope made from portions of the host's cell membrane, which aids in evading the host's immune system.
In summary, the viral genome is critical for the virus to hijack the host's cellular machinery and replicate once it has infected a host cell. Classification of viruses is also partially based on their capsid's shape, whether it is icosahedral, helical or complex.