Microorganisms, Defence Against, Etc.

Question 1

What was Pasteur’s experiment called?

Answer 1

The Swan-neck Experiment

Question 2

How did Pasteur carry out his experiment? What did he observe and what did he conclude?

Answer 2

He placed sterilised broth in three flasks. One open to the surrounding air, one sealed with a bung and the third inside a swan-neck flask.
The broths were left a few weeks.
Broth in swan-neck flask and sealed flask weren’t contaminated but open flask was.
He concluded that microbes were trapped in the ‘swan-neck’ and couldn’t reach the broth but microbes could in the open flask.

Question 3

What is HIV?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 3

Virus
Exchange of bodily fluids
No cure
Minimise risk by using condoms and not sharing needles when injecting drugs

Question 4

What is rubella?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 4

Virus
Airborne- Coughing and sneezing
MMR vaccination

Question 5

What is measles?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 5

Virus
Airborne or contact
MMR vaccination

Question 6

What is mumps?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 6

Virus
Airborne
MMR vaccination

Question 7

What is the cold and flu?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 7

Virus
Airborne
Flu vaccination

Question 8

What is Polio?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 8

Virus
Drinking faeces contaminated water
Polio vaccination

Question 9

What is Salmonella?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 9

Bacterium
Contaminated food
Treated by antibiotics
Prevented by stopping cross-contamination

Question 10

What is Gonorrhoea?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 10

Bacterium
Sexual contact
Prevented by using condoms
Treated by antibiotics

Question 11

What is Tuberculosis?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 11

Bacterium
Airborne
Prevented by BCG vaccination
Treated with antibiotics

Question 12

What is Chlamydia?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 12

Bacterium sexual
Prevented by using condoms
Treated with antibiotics

Question 13

What is athlete’s foot?

Explain what type of microorganism it is, how it is spread and how it can be treated/controlled/prevented

Answer 13

Fungus
Contact
Prevented by staying away from direct contact in areas where spores are likely to be present (e.g. Swimming pools)

Question 14

What is the first barrier against disease in the human body? How does it stop microbes entering?

Answer 14

Skin

Barrier to microbes trying to gain entry

Question 15

What is the second barrier against disease in the human body? How does it stop microbes entering?

Answer 15

Mucous membranes

Thin membranes in nose+respiratory system trap and expel microorganisms.

Question 16

What is the third barrier against disease in the human body? How does it stop microbes entering?

Answer 16

Closes wounds quickly to prevent microorganism gaining entry

Question 17

How do white blood cells fight disease?

Answer 17

Lymphocytes are a type of white blood cell. These produce antibodies when a microorganism enters the blood. Microorganisms have special chemicals called antigens. The antigens stimulate the lymphocytes to produce antibodies. The antibodies are complementary in shape to the antigens and latch on to them, linking them together. This immobilises the microorganisms which then allow phagocytes (another type of blood cell) to surround, engulf, digest and destroy the microorganisms.

Question 18

What are the 2 types of natural immunity?

Answer 18

Innate-from birth mother passes antibodies across placenta.

Acquired-develops over life(catching the diseases and recovering causes the body to produce it’s own antibodies)

Question 19

What are 2 types of artificial immunity?

Answer 19

Active-having a vaccination which causes the body to produce it’s own antibodies (as the vaccination contained a weak concentration of disease)

Passive-antibodies from another source injected into the body

Question 20

Who invented the first vaccination?

Answer 20

Jenner in 1796

Question 21

How was the first vaccination made?

Answer 21

Jenner noticed that milkmaid a who had suffered from cowpox didn’t catch smallpox. To experiment, in 1796 Jenner injected a small boy with cowpox. Some time after the boy had recovered from the illness, Jenner infected him with smallpox. The boy did not catch it however. The cowpox was very similar to smallpox and immunity has built up to both diseases in the boy.

Question 22

What are special vaccinations and who needs them? Why is this?

Answer 22

They are vaccinations that are not routinely given to people in Britain.

They are given to people who travel to some foreign countries.

This is to provide antibodies against microorganisms that they have previously not encountered.

Question 23

What are antibiotics?

Answer 23

Antibiotics are chemicals that kill bacteria or reduce their growth- they are used to combat diseases caused by bacteria.

Question 24

What can some bacteria develop against antibiotics?

Answer 24

Resistance

Question 25

What can the overuse of antibiotics lead to?

Answer 25

Bacteria gathering resistance

Question 26

What is the name given to bacteria that are resistant to many types of antibiotics?

Answer 26

Superbugs

Question 27

What is an example of a superbug?

Answer 27

MRSA

Question 28

Why is it difficult to prevent/eradicate the spread of superbugs in hospitals?

Answer 28

Antibodies have no effect

Hospitals are an antibiotic rich environment-encouraging resistance

Many patients with open wounds and weak immune systems

Question 29

Describe a typical investigation of the effect of antibiotics on bacteria in the lab.

Answer 29

One strain of bacteria is added to agar in a Petri dish using aseptic techniques. A multi disk containing 4 different antibiotics (A-D) is added to the Petri dish which is then incubated for a few days at 25*C
Bacteria growth was inhibited around the antibiotic B and to a lesser extent around antibiotic C. Antibiotics A and D has no effect on this strain bacteria.

Question 30

What did most people believe to be how bacteria contaminated objects and what year did this change?

Answer 30

Most people believed in Theory of Spontaneous Generation. This was the theory that microorganisms spontaneously appeared from non-living material, until Pasteur’s experiment in 1861.