1. Bacterial Genetics Binary fission
No Mitosis in prokaryotes
Binary fission
Asexual reproduction
High reproductive rates/short generation spans
Variation in bacteria mainly caused by mutation
Our variation mainly caused by recombination of existing alleles

2. Sources of genetic recombination:
Although there is no meiosis, recombination of alleles can occur
Sources of genetic recombination:
Transduction
Transformation
Conjugation

4. Transduction
Viruses may transfer (act as vector) DNA from one bacteria to another
New bacterial DNA may line up with a homologous section of the bacterial chromosome and recombination (crossing over) may occur
May be GENERALIZED TRANSDUCTION or SPECIALIZED TRANSDUCTION

5. Generalized transduction
Virus is in the lytic cycle
Bacterial DNA that was degraded accidentally is incorporated into viral capsid
Capsid injects bacterial DNA into new bacteria
The genes transferred are random

8. Specialized transduction
Occurs from temperate viruses (in lysogenic cycle)
Prophage comes out of bacterial chromosome and take adjacent genes with it
Only specific genes are transferred in this way

10. Conjugation Bacterial “Sex” Many bacteria have plasmids
Small circular pieces of DNA separate from chromosome
Contain only a few genes
Not necessary to bacteria’s survival
May give an advantage under certain environmental conditions

11. F plasmids Fertility plasmids
Have genes that allow bacteria to form sex pilli

12. F plasmid
Plasmids are transferred through the sex pilus during conjugation
A copy of plasmid is first made then transferred
F+ transfers to F-

14. R plasmid
Plasmid containing genes that make bacterial RESISTANT to antibiotics
May have up to 10 antibiotic resistance genes on one plasmid

15. Regulation of gene expression in prokaryotic cells
Operons
Set of structural genes that are have one promoter and are controlled by one operator
Operator determines whether transcription occurs
Regulatory gene  codes for repressor

20. trp operon
This is a repressible operon
The repressor is made in its inactive form
Operon is naturally “on”
A corepressor is required to activate the repressor and turn the operon “off”

22. Anatomy of the lac operon

23. The regulatory gene codes for the regulatory protein which is a repressor molecule

24. Active repressor prevents transcription
The repressor is MADE in its ACTIVE form
The operon is in its “OFF” position

25. Effect of lactose on the lac operon

26. The operator determines whether transcription will occur by being able to bind with a regulatory protein

27. Energy preference of E.coli

28. The concentration of glucose is inversely proportional to the concentration of cyclic AMP
Cyclic AMP binds with an activator protein and helps RNA polymerase to bind to the promoter