Quiz 2 Flashcards
What are protozoa and how are they characterized taxonomically?
- all are microscopic and unicellular
- mostly aquatic and non-photosynthetic
- characterized by mode of motility
- cause some human diseases (ex. malaria, sleeping sickness, blindness, intestinal diseases)
What are basic properties of the nonliving infectious agents in terms of their structure and size when compared to the prokaryotic/eukaryotic microbes?
- not composed of cells (not alive)
- much smaller than other infectious agents
- mostly made of just macromolecules
What is meant by the statement that viruses are obligate intracellular parasites? You also need to know their basic structure and what their genomes look like.
Viruses need a host cell’s machinery in order to replicate
- made of protein and nucleic acid
- genome can be DNA or RNA
What are prions and how do they cause disease?
Prions are abnormally folded proteins that are infectious
- cause other proteins to misfiled, and this buildup results in toxicity which results in disease in the affected organism (ex. mad cow disease)
What are viroids and how do they cause disease?
Viroids are infectious RNA molecules that cause disease in plants by binding to host mRNA and initiating destruction of cells
What are helminths and why should they and shouldn’t they be grouped with microbes? Why are they hard to treat when compared to other microbes?
Helminths are multicellular animals, specifically worms
- they are macroscopic, but most have a microscopic stage in their life cycle
they are difficult to treat due to the similarity to human cells
Why was the invention of the microscope so important?
It allowed scientists to be able to better observe specimens and for more experimentation to occur
What is meant by spontaneous generation of life and how was it disproved (by Pasteur)?
The belief that microbes and other forms of life could arise from inanimate matter
Disproved by Pasteur : boiled meat broth and left it exposed to air, and it was found that boiling killed all the microbes present and no new ones grew
What is meant by the Germ Theory? You don’t need to know about the specific findings of Semmelweis, Lister, etc. They were given to make the concept more interesting and relevant.
Theory that invisible microbes are the direct cause for many diseases
What are Koch’s postulates in general (what are they used for) and what are some of the specific criteria that he laid out?
A set of criteria used to identify the cause of a specific disease
- microbes are isolated from a diseased organism and grown in cell culture
- microbes are taken from that cell culture and inoculated into another animal, and cell culture is later taken from that animal
- both cultures are analyzed, and if the same microbes are identifies in both, it shows that the microbes from the disease host caused the same disease in the lab animal
