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Video tutorials

Supplemental Videos

Click here to watch video tutorials for exam board specific videos by A* students

Bacteria (single celled, prokaryotic)

Sigmoid growth curve shows the number of bacteria plotted against time

Total cell count

Measurement of growth

Generation time: time taken for a bacterial population to double

Viable cell count

Measurement of growth

Biological factors

Koch's Postulates1

Entry of Microorganisms (Pathogens) into the Body

Pathogenesis: How Microorganisms Cause Disease

Tuberculosis (Myobacterium tuberculosis)

Salmonella