Microbial Genetic Diversity Flashcards
What is genetic variation?
The diversity in the genetic material within a population or species.
What is genetic diversity essential for?
- Survival.
- Adaptability.
What are the 4 main mechanisms for genetic variation in bacteria?
- Conjugation.
- Transformation.
- Transduction.
- Transposition.
What is conjugation?
The transfer of genetic material via direct cell-to-cell contact.
Specifically, how is the genetic material transferred between bacterial cells?
Via a plasmid that gives a bacteria a sex pili that can move a copy of the plasmid to the new bacteria cell.
What occurs during high frequency recombinant (HFR)?
The plasmid is incorporated into the chromosome and a portion of chromosome is transferred with the plasmid when conjugation occurs.
What occurs during transformation?
Uptake of extracellular, naked DNA into the cell that is then integrated into the genome or it is degraded.
What 3 bacteria are of particular concern with gaining resistance when performing transformation?
- Streptococcus pneumoniae
- Haemophilus influenzae.
- Neisseria meningitidis.
What occurs during transduction?
Gene transfer via phage. Occasionally, some of the host genes are picked up with the phage genes and moved into another bacterial cell.
What are the 2 types of transduction?
- Generalized.
- Specialized.
What occurs during generalized transduction?
All fragments of donor DNA from any region of the chromosome have a chance to enter into transducing.
What occurs during specialized transduction?
A restricted number of genes from the donor bacteria are moved to the recipient bacteria.
In what type of phages can specialized transduction be carried out by?
Temperate phages undergoing the lysogenic phase in the donor cell.
What is moved during transposition?
- Transposable elements.
- Transposons.
- Jumping genes.
- Mobile sequences.
What is mobile DNA?
DNA that can be moved from one place or another (or a copy of which) and inserts into the target DNA.
