Microorganisms, Defence against Disease, Medicines and Drugs

Question 1

What is pasteurisation?

Answer 1

Pasteurisation is a process that kills the growth of most microbes in milk (or other products). It involves heating the milk to a high temperature (but below the boiling point) for a short period of time, followed by rapid chilling to a low temperature. This kills most bacteria present.

Question 2

Why does pasteurisation not heat the milk to boiling point?

Answer 2

Heating the milk to boiling point would affect the quality and taste of the milk.

Question 3

What are organisms that cause disease called?

Answer 3

Organisms that cause disease are called pathogens.

Question 4

Name the three main types of disease causing microorganisms?

Answer 4

Bacteria, viruses and fungi.

Question 5

What is the name given to the unique proteins that are find on the cells of the body?

Answer 5

These proteins are called antigens.

Question 6

What is the body’s initial line of defence against foreign microorganisms?

Answer 6

The initial protection is provided by the skin. This acts as a barrier to prevent the entry of microorganisms.

Question 7

Describe two ways in which the immune system works.

Answer 7

Lymphocytes produces antibodies. These stick to the antigen of the pathogen meaning they are unable to spread or reproduce.

Phagocytes engulf and digest the pathogens.

Question 8

Name five ways in which diseases can be spread and give an example for each.

Answer 8

Direct contact - athlete’s foot
In the air - colds and flu
Through body fluids - HIV/AIDS, chlamydia and gonorrhoea
Through food and water - salmonella, polio
Insects and other animals - malaria

Question 9

What causes food to become contaminated?

Answer 9

Contamination of food is caused by microorganisms in the air.

Question 10

How are measles, mumps and rubella spread and how can this be prevented?

Answer 10

Measles mumps and rubella are spread by airborne droplet infection three coughing and sneezing. They can be prevented by the MMR vaccination.

Question 11

How are you salmonella spread and how can be prevented?

Answer 11

Salmonella food poisoning is spread by contaminated food. It can be prevented by always cooking food thoroughly and making sure that raw and cooked foods are not mixed.

Question 12

How is HIV spread and how can it be prevented?

Answer 12

HIV is a virus and it is spread through the exchange of bodily fluid during sex or through infected blood. It can be prevented by using a condom or ensuring needles are not shared.

Question 13

How is athlete’s foot spread and how can it be prevented?

Answer 13

Athlete’s foot is a fungus and it is spread through direct contact. It can be prevented by avoiding direct contact in the areas where spores are likely to be present. For example, wearing flip-flops in changing areas and swimming pools.

Question 14

How do you phagocytes fight infection?

Answer 14

The cells carry out phagocytosis in which they surround and engulf pathogens, placing them in a vacuole and using their enzymes to digest and destroy it.

Question 15

How do lymphocytes fight infection?

Answer 15

Lymphocytes fight infection by producing chemicals called antibodies. These antibodies stick to the antigens, causing clumping of the microorganisms in an antibody-antigen reaction. This makes them unable to move or reproduce and also makes them an easier target for the phagocytes.

Question 16

What is immunity?

Answer 16

🚝 Immunity is where a person is protected against a particular infection.
🚝 it means that there antibody levels are high am off to combat the microorganism shouldn’t re-enter the body.

Question 17

What are the two types of immunity?

Answer 17

🚝 Active immunity - this involves the body producing its own antibodies to fight infection.
🚝 Passive immunity - this is where the body receipts ready need antibodies against the organism that causes infection.

Question 18

What is the main advantage of active immunity?

Answer 18

As the body has undergone the immune response it has produced memory cells and so it will give long-term protection.

Question 19

What is a disadvantage of active immunity?

Answer 19

It takes time to reach a high antibody level and so you are not protected for sometime after the vaccine or infection.

Question 20

What is the main advantage of passive immunity?

Answer 20

The antibiotics injected can you give a very rapid response to the infection.

Question 21

What is a disadvantage to passive immunity?

Answer 21

As the body has not undergone the immune response it is not produced memory cells and so it will only give short-term protection.

Question 22

How do vaccinations provide active immunity?

Answer 22

🚝 The patient is injected with a modified form of the pathogen.
🚝 It is treated so that it will not actually cause the disease.
🚝 The body reacts to the antigen by producing antibodies to fight the pathogen.
🚝 The antibody levels in the blood will rise (primary response)
🚝 The body will also retain memory cells that produce a response to the infection if it enters the body again (secondary response)

Question 23

What is a booster vaccination?

Answer 23

Booster vaccinations ensure that the antibody levels remain high enough over a long period of time.

Question 24

What are antibiotics?

Answer 24

Antibiotics are chemicals that can destroy harmful microbes such as bacteria.

Question 25

What was the first antibiotic?

Answer 25

First antibiotic was penicillin discovered in 1928 by Sir Alexander Fleming.

Question 26

Why will a doctor not give you an antibiotic if you have a cold?

Answer 26

Antibiotics are really only effective against bacteria and not viruses.

Question 27

Why is bacterial resistance to antibiotics a major problem and what can we do about it?

Answer 27

🚝 It is making many antibiotics useless against some infections. 🚝 it is important that we only use them if it is really necessary.

Question 28

Why do doctors ask patients to make sure that they complete a course of antibiotics even if they feeling better?

Answer 28

🚝 Some of the bacteria could survive. | 🚝 They could reproduce disease and become resistant to antibiotics.

Question 29

What is a superbug?

Answer 29

🚝 Bacteria that are resistant to all antibiotics.

Question 30

Name three things hospitals can do to deal with superbugs?

Answer 30

🚝 Increase levels of hygiene e.g. wearing gloves 🚝 Use antibiotics sparingly 🚝 Isolate patients who are infected

Question 31

What is agar?

Answer 31

Agar is a jelly like substance that contains nutrients and a high water level. It is often used to grow microorganisms.

Question 32

What is an autoclave?

Answer 32

An autoclave is a special pressure cooker used to sterilise equipment.

Question 33

What are drugs?

Answer 33

Drugs are chemicals that alter the physical or mental health of the individual that takes them.

Question 34

Name two harmful effects of drinking too much alcohol?

Answer 34

🚝 Long term drinking can damage the liver as this is where alcohol is dealt with. 🚝 Drinking heavily while pregnant can acute serious damage to the foetus including brain damage.