Final answer:
The false statement about D. viruses is that they enter a cell to complete replication they have started extracellularly; viruses must enter a host cell to begin replication.
Step-by-step explanation:
The false statement about viruses is D) Viruses enter a cell to complete the replication they have begun extracellularly. This statement is not accurate because viruses cannot begin replication outside a cell; they require the host cell's machinery to replicate. Other details about viruses that are true include: viral capsids, which can assume one of three basic shapes (helical, polyhedral, or complex), are composed of small protein subunits called capsids.
It's also true that viruses never contain both DNA and RNA simultaneously, as their genetic material is either DNA or RNA. Tobaco mosaic virus was indeed the first virus to be discovered and characterized. Lastly, some viruses have an outer envelope derived from the host cell's membrane which may include glycoproteins that help in attachment to new host cells.