Flashcards in Exam 1 Part 5 Deck (54):
What are the 3 eukaryotic microbes of clinical interest?
protozoa, fungi, and parasitic helminths
T/F: Eukaryotes can reproduce either sexually or asexually. Some even do both.
T/F: Protozoa typically lack a cell wall.
T/F: Most protozoa are pathogens
False; very few are
What kind of environment is required by protozoa?
How do most protozoa reproduce?
T/F: all protozoa produce trophozoites.
T/F: all protozoa produce cysts
false; some do, but not all
What do protozoa have that protect them from osmotic lysis?
T/F: 30% of fungi cause diseases of plants, animals and humans (mycoses)
What is the name given to the nonreproductive body of fungi?
What long, branched, tubular filaments compose the thalli of molds?
What is the term applied to fungi that produce two types of thalli?
What form of dimorphic fungi generally cause diseases?
What is the term for a tangled mass of hyphae (typically subterranean)?
T/F: all fungi have the ability to reproduce asexually.
T/F: all fungi have the ability to reproduce sexually.
false, but most do.
What is a pseudohypha?
a series of buds that remain attached to one another and to parent cell
AIDS, common colds, hemorrhagic fevers, SARS, and smallpox are all caused by what type of pathogen?
T/F: viruses can have either DNA or RNA.
What is the name for the protein coat surrounding the nucleic acid core of viruses?
What outer structure do viruses have that encloses the nucelocapsids?
Other than protection, what other function is provided by capsids and envelopes of viruses?
means of attachment to host's cells
When is the capsid of a virus removed?
once the virus is inside the host
Once inside a host, how does a virus exist?
simply as nucleic acid
T/F: viruses are always specific and infect only a particular kind of cell in a particular host.
False; some are generalists and infect many kinds of cells in many hosts
What types of organisms are susceptible to viral attack?
What viral shape consists of capsids of many shapes?
What viral shape is spiral in nature?
What viral shape consists of a geodesic dome?
What is a naked virion?
a virion without an envelope
Where is the viral envelope acquired?
from host cell during replication
What are the 3 main functions of the viral envelope?
protection, host recognition, and helping viruses enter host cells
T/F: virus replication does not usually result in death of the host cell.
T/F: viral replication is dependent on the hosts' organelles and enzymes to produce new virions.
What is lysogeny?
a modified viral replication cycle
What are prophages?
What is it called when phages carry genes that alter phenotype of a bacterium? This can turn harmless bacterium to pathogen.
Do animal cells have a cell wall?
T/F: replication of animal viruses is the same basic replication pathway of bacteriophages.
Do animal viruses have tails or tail fibers?
What are the 3 mechanisms of Entry of Animal Viruses?
Direct penetration, membrane fusion and endocytosis
What are viruses called when they remain dormant in host cells?
latent viruses or proviruses
What parasitic particles are extremely small, circular pieces of RNA and lack capsids?
What type of organisms are infected by viroids?
What are viroidlike agents?
infectious, pathogenic RNA particles that lack capsids
What organisms are infected by viroidlike agents?
fungi, NOT plants
T/F: Prions lack nucleic acid
What are the only two ways to destroy Prions?
incineration and autoclaving in sodium hydroxide
Where is prion expression most predominant?
What is the characteristic appearance of prion diseases?
spongy appearance (large vacuoles in the brain)
BSE, vCJD, and Kuru are all what kind of diseases?
Spongiform encephalopathies (prion diseases)
T/F: prions may lie behind neuronal degenerative diseases like Alzheimer's disease, Parkinson's and ALS.