Microorganisms: Disease and Applications

Question 1

What are microbes?

Answer 1

• Bacteria
• Fungi
• Virus

Question 2

Word used when microbe is grown

Answer 2

Cultured

Question 3

What is needed to grow microbes and why?

Answer 3

• Food source: proteins, simple sugars and vitamins or some make own food source
• Warm temperatures: around 25 Degrees Celsius in labs (pathogenic bacteria are likely to grow at body temperature/37 degrees Celsius)
• Moisture: water to live, grow and reproduce
• Oxygen: Aerobic conditions, anaerobic conditions encourage pathogenic bacteria to grow

Question 4

What method is used in labs when microbes are cultured?

Answer 4

Aseptic technique

Question 5

Describe how you would carry out investigation into number of bacteria present in boiled milk and milk that’s been left at room temperature for five days using aseptic technique and agar plates. Give expected results (QWC)

Answer 5

• Aseptic collection of milk samples
• Flame loop
• Inoculating and plating samples on separate plates
• Sealing Petri dishes
• Incubation at 20-25 degree Celsius for 12-24 hours
• Count colonies on plate with stale milk and boiled milk
• Boiled milk will have fewer colonies/bacteria

Question 6

Ways MRSA is controlled?

Answer 6

• Hand washing
• Thorough cleaning of hospital wards
• Alcohol gels
• MRSA screening

Question 7

How is penicillin made?

Answer 7

• The fungus Penicillium is added to liquid nutrient culture medium in fermenter
• -Supply of air and temperature controlled
• After incubation, culture medium is filtered and penicillin is extracted

Question 8

What is aseptic technique?

Answer 8

• Sterile agar jelly containing food source is poured into Petri dish
• Microbes transferred to jelly and sets, known as inoculation
• Bacteria are plated (spread over surface of agar)
• Petri dish sealed and placed in incubator at 25 degrees Celsius

Question 9

Who discovered penicillin?

Answer 9

Sir Alexander Fleming

Question 10

Who discovered smallpox vaccine?

Answer 10

Edward Jenner

Question 11

When did Edward Jenner carry out experiments on smallpox?

Answer 11

End of 18th century

Question 12

What problem can occur if antibiotics are over-used?

Answer 12

Bacteria can become resistant

Question 13

Definition of antibiotic

Answer 13

Medicine that inhibits the growth of or destroys microorganisms