The lytic infection cycle uses the following steps to infect a host cell: attachment, penetration, uncoating, biosynthesis, maturation, and release.
Correct Answer: Attachment, penetration, uncoating, biosynthesis, maturation, and release
Viruses are obligate intracellular parasites that contain either DNA or RNA but never both.
Correct Answer: Either RNA or DNA
Virions contain a capsid made up of capsomeres, either RNA or DNA and in some cases an envelope. They do not contain a capsule.
Correct Answer: A capsule
Some viruses acquire an envelope as they move out of the host cell during the release phase of the infection cycle. This envelope is made up of the plasma membrane of the host cell and contains newly synthesized viral envelope proteins.
Correct Answer: When the virus leaves the host cell
The type of host cell they infect, either animal cell, plant cells or bacterial cells, can broadly categorize viruses. Bacterial viruses are referred to bacteriophages.
Correct Answer: Infect bacteria
In the lytic cycle the host cell becomes filled with new virus particles and bursts releasing the new viral particles.
Correct Answer: The virus is causing the infected cells in the patient to burst and release many virus particles
Lipid rafts are areas of the host cell plasma membrane that are rich in cholesterol, fatty acids, and other lipids. They are more densely packed and less watery than other areas of the membrane, making them more reliable for stable viral attachment. Envelopes, spikes and capsomeres are parts of viruses.
Correct Answer: Lipid raft
Rhinovirus binds to the ICAM-1 receptor on host cells.
Correct Answer: ICAM-1 molecules
The influenza virus has spikes of hemagglutinin sticking out of its envelope, which it uses to attach to host cell receptors.
Correct Answer: Hemagglutinin
Non-enveloped viruses take advantage of normal cellular mechanisms, such as receptor-mediated endocytosis, to gain entry into the host cell.
Correct Answer: Endocytosis
Enveloped viruses enter host cells by fusing with the plasma membrane.
Correct Answer: Fusion of their envelope to the host cell membrane
Reverse transcriptase is a DNA dependent RNA polymerase that transcribes RNA into DNA.
Correct Answer: DNA using an RNA template
Viral proteins pass through the Golgi apparatus on their way from the endoplasmic reticulum to the plasma membrane. Viral proteins are sorted in the Golgi according to delivery addresses contained in their sequences.
Correct Answer: Viral proteins packaged for transit to plasma membrane
The virions of enveloped viruses with envelopes derived from the plasma membrane are assembled at the plasma membrane.
Correct Answer: Virion assembled here
Viral proteins (like cellular proteins) are synthesized by ribosomes attached to the endoplasmic reticulum.
Correct Answer: Viral proteins synthesized here
An endosome is a viral protein transit vesicle.
Correct Answer: Viral protein transit vesicle
Viral DNA and RNA is synthesized in the host cell nucleus.
Correct Answer: Synthesizes viral nucleic acid
Viruses are completely reliant on the host cell’s translational machinery for translating mRNA templates to proteins.
Correct Answer: The host cell ribosomes
Viruses do not contain ribosomes.
Correct Answer: Formation of viral ribosomes
Viruses are released from infected host cells through lysis or by budding out of the host cell.
Correct Answer: Budding and cell lysis
Many viruses burst out of the host cell and spread through body fluids, but some can spread directly from cell to cell. Viruses can also spread through the formation of syncytia which are multinucleate masses formed by the fusion of many infected cells into one gigantic cell. A syncytium allows virions to move to places far from where they were synthesized without leaving the confines of the infected syncytium and being exposed to host defenses. The presence of a syncytium is easily visible by light microscopy and can be used as a diagnostic tool for the identification of virus-infected cells.
Correct Answer: Host cell fusion with a neighbor cell, host cell rupture, and syncytia formation
Non-enveloped viruses can enter cells by hijacking the cell’s endocytosis mechanism.
Correct Answer: True
Viral genomes are transcribed quickly because large quantities of protein are needed to make new virions as quickly as possible.
Correct Answer: False
Viruses use host cell machinery to make their proteins.
Enveloped viruses are assembled at the plasma membrane.
Virus-receptor interactions are vital for infection.
Interaction between enveloped viruses and host cell can cause the host cell to change shape and expose fusion proteins, which mediate the fusion of the viral membrane with the plasma membrane.