Defending Against Disease

Question 1

How do bacteria make you feel ill?

Answer 1

• damaging your cells

- producing toxins

Question 2

How do viruses work?

Answer 2

The replicate themselves by invading your cells and using the cells’ machinery to produce many copies of themselves. The cell will usually then burst, releasing all the new viruses.

Question 3

What are pathogens?

Answer 3

Microorganisms that cause disease

Question 4

What do white blood cells do to foreign cells?

Answer 4

Engulf foreign cells and digest them

Question 5

What does a white blood cell do when it comes across a foreign antigen?

Answer 5

They produce antibodies to come and kill it. The antibodies that are produced are specific to that type of antigen and will only lock on to that. Antibodies are then produced rapidly and are carried around the body.

Question 6

What happens if someone if infected with the same pathogen again?

Answer 6

The white blood cells will rapidly produce antibodies to kil - so the person is naturally immune to that pathogen

Question 7

What do antitoxins do?

Answer 7

These counteract toxins produced by the invading bacteria

Question 8

How do white blood cells protect us from disease?

Answer 8

1. Some engulf bacteria and digest them
2. Some produce antibodies which destroy bacteria
3. Some produce antitoxins which counteract toxins produced by invading bacteria

Question 9

How do vaccinations work?

Answer 9

By injecting small amours of dead or inactive microorganisms. They carry antigens which cause your body to produce antibodies. E.g. MMR vaccine

Question 10

What does MMR stand for?

Answer 10

Measles, mumps, rubella

Question 11

Why are booster injections sometimes necessary?

Answer 11

Some vaccinations wear off over time, so booster injections are need to increase the levels of antibodies again.

Question 12

Give two advantages of vaccination?

Answer 12

1. They have helped control lots of infectious diseases that were once common in the UK.
2. Epidemics can be prevented if a large percentage of the population are vaccinated

Question 13

Give two disadvantages of vaccination?

Answer 13

1. Vaccines don’t always work - sometimes they dot give you immunity
2. You can sometimes have a bad reaction to a vaccine - but they are very rare

Question 14

What do painkillers do?

Answer 14

They are drugs that relieve pain. They don’t actually tackle the cause of the disease, they just help to reduce the symptoms

Question 15

Give an example of a painkiller

Answer 15

Aspirin

Question 16

What do antibiotics do?

Answer 16

They kill the bacteria causing the problem without killing your own body cells

Question 17

Why is it important your given the correct antibiotic?

Answer 17

Different antibiotics kill different types of bacteria

Question 18

Give an example of an antibiotic

Answer 18

Penicillin

Question 19

Why is it hard to kill viruses?

Answer 19

Because they develop using your own body cells, so it is difficult to kill the virus without killing your own body cells

Question 20

How do bacteria become resistant to antibiotics?

Answer 20

They mutate

Question 21

What is MRSA?

Answer 21

Methicillin-resistant staphylococcus aureus

Question 22

Why do bacteria become resistant?

Answer 22

• overuse of antibiotics

- inappropriate use of antibiotics

Question 23

What are antibiotics resistant to most antibiotics known as?

Answer 23

Superbugs

Question 24

Give three ways to make sure your result doesn’t get contaminated

Answer 24

• Sterilise the Petri dish before use
• Innocuoating loop used to transfer bacteria should be sterilised by passing it through a flame
• Petri dish should have a lid that is kept on before the bacteria is transferred