Preventing and Treating Disease

Question 1

What does a vaccine do?

Answer 1

Introduces small amounts of dead or inactive forms of a pathogen into your body to stimulate the white blood cells to produce antibodies. If the same pathogen re-enters the body, the white blood cells respond quickly to produce the correct antibodies, preventing infection.

Question 2

Herd Immunity

Answer 2

A large proportion of the population is immune to a pathogen, the spread of the pathogen is much reduced

Question 3

Steps on how vaccines work

Answer 3

1) Small amounts of dead or inactive pathogen are put into your body, often by injection
2) The antigens in the vaccine stimulate your white blood cells into making antibodies
3) The antibodies destroy the antigens without any risk of you getting the disease
4) You are immune to future infections by the pathogen
5) That’s because your body can respond rapidly and make the correct antibody if you had already had the disease

Question 4

Process of making monoclonal antibodies

Answer 4

1) Antigen injected into mouse
2) Lymphocytes extracted from mouse to produce antibodies specific to antigen
3) Spleen cells from lymphocytes are removed
4) These spleen cells are then fused with myeloma cells forming hybridoma cells
5) These are then divided millions of times
6) Producing a monoclonal antibody

Question 5

Using monoclonal antibodies

Answer 5

Pregnancy tests
Diagnosis of disease = bind to specific antigens found on pathogens
Measuring and monitoring = measuring levels of hormones and other chemicals in the blood
Research = identify specific molecules in a cell or tissue
Treating disease

Question 6

Treating Cancer (using monoclonal antibodies)

Answer 6

Use them to trigger the immune system to recognise, attack and destroy cancer cells
Use them to block receptors on surface of cancer cells to stop cells growing and dividing
Use them to carry toxic drugs for radiation therapy or chemicals to stop cells growing and dividing

Question 7

Advantages and Disadvantages of Monoclonal Antibodies

Answer 7

+Only bind to specific diseased of damage cells (don’t affect healthy cells)
+Could be used to treat wide range of conditions
-Expensive
+Cheaper than other treatments such as drugs
-Not that widely used or successful
-Side effects
+Doctors are prepared for side effects
-Difficult to make