Review of Viruses and Vaccination

These flashcards cover key concepts about viruses, their characteristics, reproduction cycles, HIV, and the principle of vaccination.

What are the primary characteristics of life?

Made of cells, hereditary material, growth and reproduction, metabolism, and response to stimuli.

What is a virus?

A virus is a microscopic infectious agent that requires a host cell to replicate and is composed of nucleic acid surrounded by a protein shell called a capsid.

How do viruses reproduce?

Viruses reproduce by using the host cell's machinery to replicate their nucleic acids and produce viral proteins.

What is the difference between the lytic and lysogenic cycles of bacteriophages?

In the lytic cycle, the virus causes lysis and death of the host cell after replication. In the lysogenic cycle, viral DNA integrates into the host genome and replicates along with the host cell's DNA.

What does HIV stand for and what disease does it cause?

HIV stands for Human Immunodeficiency Virus, and it causes Acquired Immune Deficiency Syndrome (AIDS).

Why is HIV difficult to eradicate?

HIV is difficult to eradicate due to its large population size, rapid mutation rate, and the ability to evolve quickly under selective pressure.

What is the purpose of a vaccine?

Vaccines stimulate the immune system to recognize and fight specific pathogens, providing immunity without causing the disease.

What is a prion?

A prion is a proteinaceous infectious particle that lacks DNA or RNA and is associated with certain neurodegenerative diseases.

What viral disease was significantly reduced by vaccination in history?

Smallpox was significantly reduced and eradicated through vaccination.

What is herd immunity?

Herd immunity occurs when a large percentage of a population becomes immune to a disease, providing indirect protection to those who are not immune.