bacteriology 3

Question 1

traditional species concept

Answer 1

Mayr (1963) Biological species concept:
A fundamental ecological and genetic unit.
Groups of interbreeding natural populations that are reproductively isolated.

Question 2

factors that influence speciation in bacteria

Answer 2

Relatively fast generation times.
Adaptive mutations.
Horizontal gene transfer and the ‘core genome’.

Question 3

agents of HGT

Answer 3

Prophage:
Phage genome inserted into the linear structure of bacterial chromosome

Plasmid:
Extra-chromosomal DNA molecule

Question 4

defining diversity

Answer 4

No coherent solution to questions regarding:
Microbial species concept.
Microbial diversity.
Obstacles:
Incomplete information on number of existing microbial species (quantitative estimate limited).
Non-operational definition of ‘microbial niche’ (eukaryote definition not useful in microbial ecology).
Loose definition of ‘species’ and ‘strains’.

Question 5

polyphasic taxonomy

Answer 5

Consensus classification – that different information into a classification containing minimum contradictions.
Information includes:
Phenotypic data (e.g. biochemical tests, fatty acid composition).
Genotypic data (e.g. DNA fingerprints).
Phylogenetic data (e.g. rDNA sequences).