Chapter 13

The size range of most viruses is __________.

20-1000 nm.

Ebola virus is one of the largest viruses, measuring approximately __________ nm.

970 nm.

Viruses are considered __________ intracellular parasites because they need a host cell to reproduce.

obligatory

Viruses contain either __________ or __________ but never both.

DNA; RNA

The __________ range of a virus is determined by specific attachment sites on host cells and cellular factors necessary for viral replication.

host

Nucleic acids in viruses can be either __________ or __________ stranded.

single; double

Capsids are made of __________ which are protein subunits.

capsomeres

The function of the capsid includes protecting nucleic acid from degradation by host __________.

nucleases

Some viruses evade immunity by __________ and changing their capsid proteins.

mutating

The envelope of a virus is composed of __________, proteins, and carbohydrates.

lipids

The family names of viruses end in __________ and genus names end in __________.

-viridae; -virus

Bacteriophages are viruses that infect __________.

bacteria

The __________ growth curve of a virus shows rapid infection, replication, and release.

one-step

During the eclipse period, __________ are present as the virus replicates inside the host.

no complete virions

The process by which viruses like bacteriophages inject their DNA into the host is called __________.

penetration

In the lytic cycle, the host cell is ultimately __________ after the virus releases new virions.

destroyed

Viral DNA can integrate into the host genome during the __________ cycle, leading to a prophage state.

lysogenic

External triggers such as stress or UV light may cause the virus to switch from the lysogenic cycle to the __________ cycle.

lytic