1
2
3
4
5
100
Give two reasons for preventing microbes from getting into food.
Prevent food related illness and prevent food spoilage
100
How could microbes contaminate food?
Microbial growth For microbial food spoilage to occur, microorganisms have to get into the food from one or more sources e.g environment, food handling, food ingredients, humans etc…
100
How does fermentation preserve food?
Lactic acid bacteria grow, produce lactic acid, lower pH, other bacteria cannot grow
100
List two of each pathogenic bacteria, viruses and parasites that can cause illness through food or water?
Bacteria – Bacillus cereus (rice) & Salmonella spp. (meat, dairy, eggs, shellfish) Viruses – Rotavirus, Norovirus Parasite – Giardia lamblia (food & water) & Helminths (worms)
100
Why does spoilage of food appear rapid when the microbes are on the food for long periods before the appearance of spoilage?
Microbes have exponential growth. Number starts low and increases exponentially.
200
List two uses for microbes in industry.
Probiotic – promotes good health, live in gut with natural flora Algae – high protein content, non-toxic
200
List two reasons for treating waste water.
Remove pathogens and toxins Prevent contamination of drinking water
200
What is B.O.D?
Biochemical Oxygen Demand
200
What does BOD indicate?
Determines the levels of biological degradable organic material present in water. High level indicates high levels of organic material in water tested
200
What is the main process in secondary sewage treatment?
Hydrolysis – reaction where complex macromolecules are split into smaller parts by reacting with H20
300
Give 3 uses for Bacteriophage.
Possible treatment for bacterial infection Identify pathogenic bacteria Recombinant DNA technology
300
What are the advantages of using HIV as a vector for gene therapy?
Ideal vector = deliver transgene to specific target cell and express gene sufficiently HIV is a retrovirus, reverse transcriptase generates DS-DNA, integrated into host chromosome, delivers and expresses gene
M
e
n
u