Final answer:
Viruses that rely on internal pressure to inject their DNA into host cells have a narrow acceptance of genome size.
Step-by-step explanation:
Many viruses indeed use pressure to inject their DNA into host cells. Due to the rigid structure of the capsids, viruses do show a narrow acceptance of genome size. The size of the genome must be precise for it to be efficiently packaged within the capsid and to ensure that it retains the high internal pressure necessary for injection into a host cell.
Viruses must navigate a tight balance, as too much genetic material could prevent effective packaging, while too little might not retain the pressure required for the transfer of genetic material. Virions are produced in the host cell following successful injection and takeover of the cell's machinery, relying on the host's replication proteins for the synthesis of new viral DNA, RNA, and proteins.
These components are essential for the assembly of new virus particles. If the viral genome is altered significantly in size, this precise packaging process and subsequent injection could be compromised, leading to an inefficient viral replication process.