B6 - Preventing and Treating Disease

Question 1

<p>Which type of blood cells fight disease?</p>

Answer 1

<p>White blood cells</p>

Question 2

<p>Name the type of white blood cell that engulfs pathogens</p>

Answer 2

<p>Phagocyte</p>

Question 3

<p>Name the type of white blood cell that produces antibodies</p>

Answer 3

<p>Lymphocyte</p>

Question 4

<p>When you get a vaccination what does the doctor actually inject you with?</p>

Answer 4

<p>A weakened/dead form of the pathogen that still retains the antigens (receptors).</p>

Question 5

<p>What is an antigen?</p>

Answer 5

<p>All cells (including human body cells) have receptors on their surface. These are called antigens.</p>

Question 6

<p>Define herd immunity.</p>

Answer 6

<p>Herd immunity involves vaccinating a large proportion of the population against a certain pathogen (e.g. flu vaccine).This is to reduce the number of people getting the disease and therefore it reduces the spread of the disease.</p>

Question 7

<p>Explain how a person develops immunity to a certain disease after receiving a vaccination.</p>

Answer 7

<ul> <li>A <strong>dead/weakened/inactive</strong> pathogen is injected into the patient’s bloodstream. The pathogen still retains the antigens.</li> <li>Specific lymphocyte recognises the <strong>specific antigens</strong> produce large amounts of the correct antibody.</li> <li>Pathogen is killed by the antibodies.</li> <li>‘<strong>M</strong><strong>emory lymphocytes</strong>’ remain in the bloodstream.</li> <li>This provides immunity to that specific pathogen.</li> <li>If the same pathogen re-enters the body the white blood cells respond (more) quickly to produce large amounts of the correct antibodies, preventing infection.</li></ul>

Question 8

<p>How is a monoclonal antibody made?</p>

Answer 8

<p>Lymphocytes make antibodies but cannot divide. Tumour cells do not make antibodies but can divide rapidly to make a clone of cells. Scientists combine mice lymphocytes with a tumour cell to create a hybridoma cell. The hybridoma cell divides to make a large number of identical clones that all produce the same antibody. These antibodies are collected and purified. They are monoclonal antibodies -<strong>antibodies produces from a single clone of cells</strong></p>

Question 9

<p>What is a monoclonal antibody?</p>

Answer 9

<p>•Monoclonal antibodies are <strong>produced from a single clone of cells</strong>, consisting of identical antibody molecules.</p>

Question 10

<p>How do monoclonal antibodies work?</p>

Answer 10

<p>The <strong>antibodies are specific to one binding site</strong> on <strong>one particularantigen</strong> and so are able to target a specific chemical or specific cells in the body.</p>

Question 11

<p>When a B lymphocyte fuses with a tumour cell, what is the resulting cell formed called?</p>

Answer 11

<p>A hybridoma cell</p>

Question 12

<p>Name a use for monoclonal antibodies in medicine.</p>

Answer 12

*Pregnancy tests
• Diagnosis of disease
*Measuring and monitoring levels of hormones/other chemicals in the blood

Question 13

<p>Monoclonal antibodies are present in pregnancy testing kits. How do monoclonal antibodies indicate pregnancy?</p>

Answer 13

<p>•The blood of pregnant women contains a hormone called <strong>hCG</strong> that is made early in pregnancy.</p>

<p>•Tiny amounts of this hormone are passed out of the body in the <strong>urine</strong>.</p>

<p>•<strong>Monoclonal antibodies</strong> in the pregnancy test <strong>bind to the HCG hormone</strong> if it is present.</p>

<p>•This <strong>produces a colour change</strong> and positive result.</p>

Question 14

<p>Name some possible side effects of monoclonal antibodies.</p>

Answer 14

• Fever
• Chills
• Vomiting
• Nausea

Question 15

<p>What are hybridomas?</p>

Answer 15

<p>cells created during the production of monoclonal antibodies by the fusion of an antibody-specific lymphocyte and a tumour cell</p>

Question 16

<p>What is a vaccine?</p>

Answer 16

<p>dead or inactive pathogenic material used in vaccination to develop immunity to a disease in a healthy person</p>

Question 17

<p>Describe how “cadida albicans” Monoclonal Antibodies and a fluorescent dye could be used to see if there are any “cadida albicans” on a slide:</p>

Answer 17

<p>The monoclonal antibodies should first bind with the fluorescent dye. The fluorescent mAbs should then be placed on the slide. If “cadida albicans” is present, the monoclonal antibodies would bind to the antigens on the pathogen. This would then be able to be viewed under a microscope to see if there are any pathogens present.</p>

Question 18

<p>Suggest 1 reason why mAbs made using human lymphocytes are more successful in treating diseases in humans than mAbs made using mice lymphocytes:</p>

Answer 18

<p>The body is less likely to reject the mAbs made from human lymphocytes, whereas it is more likely to reject the mAbs made from mice lymphocytes</p>

Question 19

What type of disease are monoclonal antibodies often used to treat?

Answer 19

Cancer

Question 20

How are monoclonal antibodies used to treat cancer?

Answer 20

• They may trigger the immune system to recognise, attack, and destroy cancer cells
• They may block receptors on the surface of cancer cells and so stop the cells dividing and growing
• They may carry toxic drugs or radioactive substances which stops the cells growing and dividing

Question 21

What are the advantages of using monoclonal antibodies to treat cancer?

Answer 21

Unlike other treatments, it can treat cancer without harming any other cells in the body

Question 22

What are the disadvantages of monoclonal antibodies ?

Answer 22

• Fever
• Chills
• Vomiting
• Nausea

Question 23

How are viruses introduced to the lymphocytes?

Answer 23

They are injected into the mouse and then the lymphocytes are removed after they have formed an immune response