Biology Topic 8 Non-Communicable Diseases

Question 1

Traditionally drugs were extracted from plants and microorganisms.

Answer 1

The heart drug digitalis originates from foxgloves.
The painkiller aspirin originates from willow.
Penicillin was discovered by Alexander Fleming from the Penicillium mould.

Question 2

New medical drugs have to be

Answer 2

tested and trialled before being used to check toxicity, efficacy and dose.

Question 3

Preclinical testing is done in a
and uses

Answer 3

laboratory using cells, tissues and live animals.

Question 4

Clinical trials use healthy volunteers and patients and

Answer 4

Very low doses of the drug are given at the start of the clinical trial.
If the drug is found to be safe, further clinical trials are carried out to find the optimum dose for the drug.
In double blind trials, some patients are given a placebo, which contains inactive drugs in order to compare the effect of the drug being tested.

Question 5

Results of testing and trials are published only after

Answer 5

scrutiny by peer review to help prevent false claims.

Question 6

Health is
diseases cause

Answer 6

the state of physical and mental wellbeing. Diseases, both communicable and non-communicable, are major causes of ill health.

Question 7

Other factors including————–may have a profound effect on both physical and mental health.

Answer 7

diet, stress and life situations

Question 8

Different types of disease may interact:

Answer 8

Defects in the immune system mean that an individual is more likely to suffer from infectious diseases.
Viruses living in cells can be the trigger for cancers.
Immune reactions initially caused by a pathogen can trigger allergies such as skin rashes and asthma.
Severe physical ill health can lead to depression and other mental illness.

Question 9

Risk factors are linked to an increased rate of a disease. These can be

Answer 9

aspects of a person’s lifestyle
substances in the person’s body or environment.
Many diseases are caused by the interaction of a number of factors.

Question 10

A causal mechanism has been proven for some risk factors (see below), but not in others.

Answer 10

The effects of diet (high fat, high cholesterol), smoking and lack of exercise on cardiovascular disease.
Obesity as a risk factor for Type 2 diabetes.
The effect of alcohol on the liver and brain function.
The effect of smoking on lung disease and lung cancer.
The effects of smoking and alcohol on unborn babies.
Carcinogens, including ionising radiation, as risk factors in cancer

Question 11

Cancer is

Answer 11

the result of changes in cells that lead to uncontrolled growth and division.

Question 12

Benign tumours are

Answer 12

growths of abnormal cells which are contained in one area, usually within a membrane. They do not invade other parts of the body.

Question 13

Malignant tumour cells

Answer 13

cancers. They invade neighbouring tissues and spread to different parts of the body in the blood where they form secondary tumours.

Question 14

Scientists have identified lifestyle risk factors for various types of cancer:

Answer 14

Smoking
Obesity
Common viruses
UV exposure
There are also genetic risk factors for some cancers.

Question 15

Describe how monoclonal antibodies are produced

Answer 15

Mouse lymphocytes stimulated to produce a specific antibody.
Lymphocytes combined with a tumour cell to form hybridoma cells.
Hybridoma cells both divide and make the antibody.
Single hybridoma cells are cloned to produce many identical cells that all produce the same specific antibody.
A large amount of the antibody can be collected and purified.

Question 16

Monoclonal antibodies are specific to

Answer 16

specific to one binding site on one protein antigen. They can therefore target a specific chemical or type of cell within the body.

Question 17

Describe uses of monoclonal antibodies:

Answer 17

Diagnosis: in pregnancy tests a monoclonal antibody binds to the hormone hCG produced by the embryo.
In laboratories: monoclonal antibodies are used to measure the levels of hormones and other chemicals in blood, or to detect pathogens.
In research: to locate or identify specific molecules in a cell or tissue by binding to them with a fluorescent dye.
To treat some diseases: for cancer the monoclonal antibody can be bound to a radioactive substance, a toxic drug or a chemical which stops cells growing and dividing.

Question 18

Monoclonal antibodies have more

Answer 18

side effects than expected. They are not yet as widely used as everyone hoped when they were first developed.

Question 19

Explain how monoclonal antibodies can be used in pregnancy tests

Answer 19

If HCG is present, the monoclonal antibody will bind with HCG and carry it down the strip.
These antibodies are specific, so will only bind to HCG
The monoclonal antibodies will release a dye which will cause a colour change to the test area on the stick
The antibodies will also bind to another area on the stick, which acts as the control strip

Question 20

Q2) Why is it important for tests (pregnancy/covid) to have control strips?

Answer 20

The control strip indicates that the test was taken correctly and that it works as it should. If the control strip is negative, then the test is not valid and should be taken again.

Question 21

Q4) Explore what cancers can be influenced by lifestyle factors?

Answer 21

Lung Cancer - smoking
Skin Cancer - sun exposure and sun beds
Liver cancer - alcohol consumption