1. Bacterial Reproduction and Uses
The two main mechanisms used by Bacteria for Reproduction
How Transformation was investigated.
Bacteria as Pathogens and Benefactors
Key Terms: Binary Fission, Conjugation, Transformation, Transduction, Endotoxin, Exotoxin.

3. Binary Fission – Vertical Gene Transfer

4. Transformation & Transduction
Horizontal Gene Transfer

5. Conjugation - Horizontal Gene Transfer

6. Conjugation

9. Mechanisms of Transfer

10. Boardworks AS Biology Infectious Diseases
Mechanisms of disease
Boardworks AS Biology
Infectious Diseases
Pathogens can cause disease in two main ways:
damaging cells – for example, malarial parasites cause disease symptoms by bursting red blood cells.
producing toxins – exotoxins are secreted by a living, normal pathogen, whereas endotoxins are released when the pathogen is damaged.
For example, the symptoms of cholera are caused by an exotoxin secreted by the bacteria Vibrio cholerae. It increases the secretion of chloride ions into the lumen of the intestines, which can lead to severe diarrhoea.

11. Bacterial Toxins Endotoxins Exotoxins
Lipopolysaccharides (this is the substance that makes up the outer layer of Gram –ve bacteria)
Rarely fatal – may cause
symptoms such as fever,
vomiting, diarrhoea
Examples include E. coli and salmonella
Soluble proteins (produced and released into the body by bacteria)
Often very dangerous or even
fatal - have a variety of effects
such as damage to cell
membranes or acting as
competitive inhibitors to
neurotransmitters
Examples include C. botulinum

12. Beneficial Bacteria
In your body bacterial cells out-number your own human body cells by 10:1 !!!!!
There are 1014 bacteria in your body !!!!
They weigh about 2.2 Kg !!!!

13. Infectious Diseases Videos
Top 10 Infectious Diseases (best one)
25 most deadly diseases in human history
10 deadliest diseases in human history

14. Activities
1) Summarise the role of Beneficial bacteria in: a) the gut b) Ecosystems i) as part of the Nitrogen Cycle (Hint: What do Nitrifying, Decomposing and Nitrogen-fixing bacteria do?) ii) as part of the Carbon Cycle 2) Use the sheet ‘Invading the Body’ to show how infections can be passed from person to person. 3) Complete ‘Pathogens and Infection’ (You may need to use the additional textbooks or the Internet to research some of the diseases)