Outcome 1 - Protozoa Flashcards
Protozoa are
Unicellar eukaryotic micro-organisms that can undergo mutation, recombination and random assortment
Name two diseases caused by protozoa
Trypanosoma brucei - sleep sickness
Plasmodium falciparum - causes malaria
Name a non-pathogenic protozoa
Paramecium aurelia
Paramcium aurelia contains 2 types of ____
Nuclei - a macronucleus and a micronucleus
How do Paramecium aurelia reproduce
They can reproduce asexually through binary fission and sexually through conjugation
A special type of inheritanceis found in Paramecium aurelia -
Kappa particles symbiotic bacterium that are responsible for the production of paramecin which is toxic to sensitve strains (those that dont possess Kappa)
The production of kappa particles is dependent on
The posession of the dominant K allele - killer strains are KK or Kk and sensitive strains are kk and the possesion of Kappa particles
Kappa particles are inherited
when the cytoplasm is shared during conjugation and the inheritance of Kappa particles is dependent on the length of conjugation between a Killer strain and a sensitive strain
Describe Trypanosoma brucei
A flagellated parasitic protozoa that causes sleep sickness. In humans it produces a thick layer of variant surface glycoproteins that protect it from antibodies. Vast amounts of VSG can recombine to produce new variants
Describe antigenic variation in a Trypanosomaa brucei population
VSG genes are constantly re-arranging by recombination, during immune response the host will produce antibodies against a specific VSG protein allowing strains with a different VSG protein to survive
What is meant by a switching mechanism
In individual bloodstream forms of Trypanosoma brucei it will express a single VSG gene. The active transcritpion site is located in the sub-telemoric region of the chromosome an using recombination silent VSG genes can be inserted into the active transcription site meaning a different VSG gene will be expressed
