Chapter 19 Flashcards
What is a virus?
A virus is an infectious particle consisting of genes packed in a protein coat.
What can Viruses cause?
Disease
What can Viruses not do?
Viruses cannot carry out metabolic activities outside the host cell
What did Adolf Mayer study?
Tobacco mosaic disease
What is tobacco mosaic disease?
Stunts growth of tobacco and gives leaves moulted colorisation.
How was tobacco mosaic disease caused?
Caused by unusually small bacteria that were invisible under a microscope
How does pathogen replicate?
Pathogen only replicates within infected host cell.
Why is the simple structure helpful?
Helps with the biological system.
What genes are in viruses?
Double or Single stranded DNA Or Double or Single stranded RNA
How is a DNA or RNA virus detemined?
Depends on the nucleic acid that makes up the genome.
What is a genome?
A single linear or circular molecule of nucleic acid
Whats the smallest size to largest size of Virus genes?
3 - 2,000
What is a capsid?
A protein shell enclosing the viral genome.
What are the different shapes?
rod-shaped, polyhedral
What are capsids build from?
Large number of protein subunits called caposomeres.
What is TMV viruses made from?
Rigid, rod shaped capsid made from 1000 molecules of protein organised in a helix.
What is Adenoviruses?
Typically infect respiratory tracts of animals.
252 identical protein molecules arranged in a polyhedral capsid with 20 triangular facets.
What are viral envelopes?
