Characterizing and Classifying Viruses, Viroids, and Prions

What are viruses?

• C. Fungi causing infections

• A. A type of bacteria

• D. Parasitic worms

• B. Acellular infectious agents with DNA or RNA

What is the extracellular state of a virus called?

• C. Virion

• D. Envelope

• B. Nucleocapsid

• A. Capsid

How do viruses recruit the cell's metabolic pathways?

What is the primary way scientists categorize and classify viruses?

• B. By their shape

• C. By the nature of their genomes

• D. By their hosts

• A. By their size

Which type of viruses infect only particular host cells?

• D. Specialists

• C. Specialists

• B. Specificists

• A. Generalists

What is the role of capsids in viruses?

• C. Respond to the environment

• B. Carry out metabolic pathways

• A. Provide protection for viral nucleic acid

• D. Grow independently

How do DNA viruses of animals replicate?

• A. In the cytoplasm

• D. Replicate in the cell wall

• C. Use RNA intermediary

• B. Replicate in the nucleus

What is the characteristic appearance of spongiform encephalopathies caused by prions?

• D. Increased brain mass

• C. No effect on brain structure

• B. Large vacuoles in the brain

• A. Smooth brain surface

How are prions destroyed?

• B. Exposure to UV light

• D. Ethanol disinfection

• A. Incineration or autoclaving in concentrated sodium hydroxide

• C. Treatment with antibiotics

Why did scientists initially resist the idea of an infectious protein?

• A. Lack of evidence

• B. Complexity of the concept

• C. Ethical concerns

• D. Difficulty in research