Final answer:
Virus infections involve attachment to host cell receptors, replication of viral DNA in the host cell, assembly of new viruses, and lysis of the host cell.
Step-by-step explanation:
Virus infections begin with the attachment of the virus to receptors on the host cell surface. The virus then penetrates the cell membrane or cell wall, and its protein coat is removed, allowing the genetic material to be injected into the cell. The host cell replicates the viral DNA and produces the proteins the virus needs. The new viruses are assembled, eventually causing the host cell to burst in a process called lysis. Some viruses take a portion of the host cell membrane to form an envelope around the capsid during lysis.