Health and Disease

Question 1

What is health, and what is it not?

Answer 1

Health is a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.

Question 2

How can alcohol and smoking affect health?

Answer 2

Alcohol can cause liver disease and smoking can cause cardiovascular disease.

Question 3

How do you calculate BMI?

Answer 3

BMI = weight/height^2

Question 4

Explain treatments for cardiovascular disease.

Answer 4

• Statins are long-term drugs that help to reduce blood cholesterol levels.
• Stents are minor surgical inserts to keep coronary arteries stretched open.
• Heart transplants are required in case of heart failure.
• Lifestyle changes may not be enough to sort out all issues in and of itself.

Question 5

Explain the spread of some common infections.

Answer 5

• Cholera causes diarrhoea by waterborne bacteria.
• Tuberculosis causes lung damage by droplet bacteria.
• Chalara ash dieback causes leaf loss and bark lesions by airborne fungi.
• Malaria causes lung and liver damage by protists from infected female Anopheles mosquito bites.
• HIV causes white blood cell destruction, leading to AIDS, by viruses in transferred bodily fluids.
• Helicobacter pylori causes stomach ulcers by bacteria in contaminated food.
• Ebola causes haemorrhagic fever by viruses in contacted bodily fluids.

Question 6

Describe the life cycle of a virus.

Answer 6

DNA injected into host cell after attachment.
Lysogenic pathway: DNA integrated into host chromosomal DNA, so recreated during mitosis. Stays quiet, until it jumps into lytic cycle.
Lytic pathway: DNA circularizes (similar to plasmid), then copies synthesised until host lyses, releasing all viruses.

Question 7

Explain how antibiotics work to treat bacterial infections but are useless against viral infections.

Answer 7

Antibiotics damage the bacterial cells by inhibiting their cellular processes, but do not damage the host cells. Viruses reproduce within host cells, so are not affected. It is very difficult to damage a virus without affecting the host cell - what antiviral medicine attempts to do.

Question 8

What are monoclonal antibodies and how are they used in pregnancy testing?

Answer 8

Monoclonal antibodies are cloned antibodies that all bind to the same antigen. Pregnant women’s urine contains HCG, so monoclonal antibodies that bind to HCG are used in pregnancy testing.