Skip to main content
뒤로

General Biology: Viruses

컨트롤 버튼이 '내비게이션' 모드로 변경되었습니다.
1/21

이 집합의 용어 (21)

  • What is a virus?
    A virus is an infectious particle consisting of genes packaged in a protein coat. It cannot reproduce or carry out metabolism outside a host cell.
  • What are the main components of a virus?
    A virus consists of nucleic acid (DNA or RNA) enclosed in a protein coat called a capsid. Some viruses also have a membranous envelope.
  • How are viruses classified based on their genome?
    Viruses are classified as DNA or RNA viruses, with genomes that can be single- or double-stranded, linear or circular.
  • What is a capsid and what is it made of?
    A capsid is the protein shell enclosing the viral genome, built from protein subunits called capsomeres.
  • What is the function of viral envelopes?
    Viral envelopes, derived from host membranes, surround some viruses and contain viral and host molecules that help the virus infect host cells.
  • What is a bacteriophage?
    A bacteriophage (phage) is a virus that infects bacteria, characterized by an elongated capsid head and a protein tail used to inject DNA into the host.
  • What does it mean that viruses are obligate intracellular parasites?
    Viruses can replicate only inside host cells, using the host's machinery to produce viral components.
  • What is the lytic cycle in phages?
    The lytic cycle is a viral replicative cycle that produces new phages and lyses the host cell, killing it.
  • What is the lysogenic cycle in phages?
    The lysogenic cycle integrates viral DNA into the host chromosome as a prophage, replicating without killing the host until triggered to enter the lytic cycle.
  • How do bacteria defend against phages?
    Bacteria use surface protein mutations, restriction enzymes to cut foreign DNA, and the CRISPR-Cas system to target and destroy phage DNA.
  • What is the CRISPR-Cas system?
    A bacterial adaptive immune system that stores phage DNA sequences and uses Cas proteins to recognize and cut invading phage DNA.
  • How do animal viruses differ from bacteriophages?
    Animal viruses often have RNA genomes and membranous envelopes, unlike most bacteriophages.
  • What is a retrovirus?
    A retrovirus is an RNA virus that uses reverse transcriptase to copy its RNA genome into DNA, which integrates into the host genome as a provirus.
  • What is a provirus?
    A provirus is viral DNA integrated permanently into the host genome, transcribed into RNA for viral protein synthesis and new virus genomes.
  • How do viruses evolve?
    Viruses likely evolved from mobile genetic elements like plasmids and transposons and continue to evolve rapidly through mutation and recombination.
  • How do viruses cause disease in animals?
    Viruses damage cells by lysing them, releasing enzymes, producing toxins, or having toxic molecular components.
  • What is a vaccine?
    A vaccine is a harmless derivative of a pathogen that stimulates the immune system to defend against the harmful pathogen.
  • What causes emerging viral diseases?
    Emerging viruses arise from mutation, spread from isolated populations, or transmission from animals to humans.
  • How do influenza viruses cause epidemics and pandemics?
    Influenza viruses mutate rapidly and reassort their segmented RNA genomes, creating new strains that can cause widespread outbreaks.
  • How do plant viruses spread?
    Plant viruses spread by horizontal transmission through damaged cell walls and vertical transmission from parent to offspring.
  • What are prions?
    Prions are infectious misfolded proteins that cause degenerative brain diseases by converting normal proteins into the misfolded form.