Viruses, Bacteria, Fungi Flashcards
What are viruses?
Non-cellular particle made up of genetic material (DNA and RNA), and proteins.
What are viruses measured in?
Nanometers
What are examples of common viruses?
Cold, measles, smallpox, Ebola, AIDS, mono, influenza, warts
What are shapes a virus can come in?
Helical, polyhedral, complex
What’s another name for the virus head?
Capsid
Where is genetic information kept?
The capsid
Where can viruses reproduce?
Inside a host
Are viruses specific to which species they attack?
Yes
What is the lytic cycle?
- Virus attaches itself to host cell
- Host is injected with DNA or RNA
- The host cell makes copies of viral genetic material
- The new DNA or RNA is packaged into viral particles
- The host cell lyses and releases new viral particles to attack more cells
What is the lysogenic cycle?
Some viruses have the ability to lay dormant.
- The virus attaches itself to a host
- Host is infected
- Viral DNA is incorporated into host DNA forming a prophage.
- The viral DNA is replicated during cell division of the host cell, but the viral gene remains dormant.
- When immune system is suppressed, viral DNA becomes active and enters the lytic cycle
What are bacteria?
Prokaryotic, unicellular, most have a single circular chromosome. They contain ribosomes, can reproduce sexually or asexually. Some are autotrophs, some are heterotrophs
What are bacteria cell walls made of?
Peptidoglycan
How do bacteria attach to one another or a host?
With a sticky coating called the capsule
What do the inside of bacteria cells have that make them unique?
A DNA ring called plasmids
How do bacteria move?
With a long tail called a flagellum. Not all bacteria have this.
What are the pilus?
Short hair-like proteins that help bacteria stick to surfaces. Used in sexual reproduction
What are bacteria shapes?
Bacillus (rod shaped), caccus (sphere shaped), spirillum (spiral shaped)
What may bacteria do after cell division?
Form pairs (prefix diplo), chains (prefix strepto), or colonies (prefix staphylo)
What do gram positive bacteria retain?
The stain crystal violet. They appear purple under a microscope