Extended Response Question Flashcards
The parasitic niche
Parasitism is a symbiotic interaction between a parasite and its host. (+/-)
A parasite gains benefit in terms of nutrients at the expense of its host.
Unlike in a predator prey relationship, the reproductive potential of the parasite is greater than that of the host.
Most parasites have a narrow (specialised) niche as they are very host specific.
As the host provides so many of the parasites needs, many parasites are degenerate, lacking in structures and organs found in other organisms.
Ecto + endo parasites
Viruses
Viruses are parasites that can only replicate INSIDE a host cell
Viruses contain genetic material in the form of DNA or RNA, packaged in a protective protein coat.
Some viruses are surrounded by a phospholipid membrane derived from host cell materials.
The outer surface of a virus contains antigens that a host cell may or may not be able to detect as foreign.
What are some factors that increase transmission rates ?
Overcrowding of hosts when they are at a high density
Mechanisms, such as vectors and waterborne dispersal stages, that allow that parasite to spread even if infected hosts are incapacitated.
Importance of controlling pH in imunoassays
pH affects the proteins structure and interactions between the R groups.
The altered protein will have a reduced affinity for the substrate.
Antigenic variation
A rapid change of the antigen surface proteins
So, the appropriate memory cells are not present
A new vaccine produced must contain new antigens
Causes of a sex change
Parasitic infection
Competition
Size
Temperature of incubation
