12.7

Question 1

What is the difference between communicable and non-communicable diseases?

Answer 1

Communicable diseases are caused by pathogens and can be passed from person to person.

Non-communicable diseases cannot be passed between individuals and include heart disease, most cancers, and many nervous, endocrine, and digestive disorders.

Question 2

What is a pathogen?

Answer 2

A microorganism that causes disease, such as bacteria, viruses, fungi, or protists.

Question 3

What is natural active immunity?

Answer 3

Immunity gained after an infection where the immune system produces antibodies and memory cells, providing long-term protection.

Question 4

How does natural passive immunity protect a new-born?

Answer 4

Antibodies cross the placenta and are also delivered through colostrum in breast milk, providing short-term immunity until the baby’s immune system matures.

Question 5

What is colostrum and how does it help immunity?

Answer 5

Colostrum is the first milk produced by the mother, rich in antibodies that pass into the baby’s bloodstream without being digested.

Question 6

What is artificial passive immunity?

Answer 6

Injection of ready-made antibodies from another organism, providing immediate but short-term protection (e.g., tetanus, rabies).

Question 7

What is artificial active immunity?

Answer 7

Immunity developed from vaccination where a safe form of an antigen triggers an immune response and memory cell formation.

Question 8

What happens during vaccination?

HINT: SOME ANTS PREPARE SWIFTLY

Answer 8

Some = Safe pathogen (weakened, killed, or part of pathogen used—no risk of disease)

Ants = Antigen introduced into the bloodstream

Prepare = Primary response occurs (antibodies + memory cells made)

Swiftly = Secondary response is rapid on real exposure—stops illness before symptoms

Question 9

What forms can vaccines take?

Answer 9

• Inactivated/killed bacteria/viruses (e.g., whooping cough)
• Live, attenuated strains (e.g., polio, BCG, rubella)
• Detoxified toxins (e.g., diphtheria, tetanus)
• Isolated antigens (e.g., influenza)
• Genetically engineered antigens (e.g., hepatitis B)

Question 10

Why are booster shots needed?

Answer 10

To extend the duration of immunity if it wanes over time.

Question 11

What is an epidemic?

Answer 11

An epidemic is a local/national outbreak of disease.

Question 12

What is a pandemic?

Answer 12

A pandemic is a global outbreak.

Question 13

What is herd immunity?

Answer 13

When a large proportion of the population is immune, reducing disease spread and protecting those who are not immune.

Question 14

Why is it hard to develop vaccines for malaria and HIV?

Answer 14

• Malaria (Plasmodium) hides inside erythrocytes and changes antigens.
• HIV attacks immune cells (T helper cells, macrophages), disabling the immune response.

Question 15

What are the two roles of medicines?

Answer 15

To treat symptoms (e.g., painkillers, antacids) and to cure disease (e.g., antibiotics, chemotherapy).

Question 16

What was the first widely used antibiotic and who discovered it?

Answer 16

Penicillin, discovered by Alexander Fleming in 1928; industrialised by Florey and Chain.

Question 17

What are the six common medicinal drugs derived from living organisms?

Answer 17

1. Penicillin.
2. Docetaxel/Paclitaxel.
3. Aspirin.
4. Prialt.
5. Vancomycin.
6. Digoxin.

Question 18

Medicinal Drug: Penicillin

a) What are the sources of this medicinal drug?

b) What is the action/uses of this medicinal drug?

Answer 18

Sources:
Commercial extraction originally from mould growing on lemons.

Action:
Antibiotic – the first effective treatment against many common bacterial diseases.

Question 19

Medicinal Drug: Docetaxel/Paclitaxel

a) What are the sources of this medicinal drug?

b) What is the action/uses of this medicinal drug?

Answer 19

Sources:
Derived originally from yew trees

Action:
Treatment of breast cancer.

Question 20

Medicinal Drug: Aspirin

a) What are the sources of this medicinal drug?

b) What is the action/uses of this medicinal drug?

Answer 20

Sources:
Based on compounds from willow bark.

Action:
* Painkiller
* Anti-coagulant
* Anti-pyretic (reduced fever)
* Anti-inflammatory

Question 21

Medicinal Drug: Prialt

a) What are the sources of this medicinal drug?

b) What is the action/uses of this medicinal drug?

Answer 21

Sources:
Derived from the venom of a cone snail from the oceans around Australia

Action:
New pain-killing drug 1,000 times more effective than morphine

Question 22

Medicinal Drug: Vancomycin

a) What are the sources of this medicinal drug?

b) What is the action/uses of this medicinal drug?

Answer 22

Sources:
Derived from a soil fungus

Action:
One of our most powerful antibiotics

Question 23

Medicinal Drug: Digoxin

a) What are the sources of this medicinal drug?

b) What is the action/uses of this medicinal drug?

Answer 23

Sources:
Based on digitoxin, originally extracted from foxgloves.

Action:
Powerful heart drug used to atrial fibrillation and heart failure.

Question 24

Why is biodiversity important in medicine development?

Answer 24

Undiscovered organisms may contain compounds crucial for developing life-saving drugs.

Question 25

What is pharmacogenetics?

Answer 25

The study of how individual genetic makeup affects drug response, enabling personalised medicine.

Question 26

Give an example of pharmacogenetics in cancer treatment.

Answer 26

HER2-positive breast cancer can be treated with Herceptin or Lapatinib, reducing deaths by up to 50%.

Question 27

What is synthetic biology in medicine?

Answer 27

Using genetically engineered organisms (e.g., bacteria, mammals) to produce drugs or proteins for therapeutic use.

Question 28

How is nanotechnology used in synthetic biology?

Answer 28

To deliver drugs directly to specific cells (e.g., in tumours or infected cells).

Question 29

What is selective toxicity?

Answer 29

The ability of antibiotics to kill or inhibit bacteria without harming human cells.

Question 30

Why are antibiotics becoming less effective?

Answer 30

Overuse and misuse have led to antibiotic-resistant bacteria due to natural selection and rapid reproduction.

Question 31

What are MRSA and C. difficile?

Answer 31

* MRSA: A strain of Staphylococcus resistant to methicillin. * C. difficile: Gut bacterium that produces toxins, often after helpful bacteria are killed by antibiotics.

Question 32

How do bacteria become resistant to antibiotics?

Answer 32

Mutations during reproduction may make bacteria immune to antibiotics; these survive and reproduce rapidly, passing on resistance.

Question 33

How does farming contribute to antibiotic resistance?

Answer 33

Routine use of antibiotics in animal feed (in some countries) selects for resistant strains, though this is banned in the UK.

Question 34

How can antibiotic resistance be reduced?

Answer 34

* Minimise antibiotic use. * Complete antibiotic courses. * Maintain high hygiene standards in hospitals and care homes.

Question 35

What is the current challenge with antibiotic discovery?

Answer 35

Resistance is evolving faster than new antibiotics can be developed.

Question 36

What is the Longitude Prize?

Answer 36

A £10 million prize for developing a quick, cost-effective, accurate test for bacterial infections to promote responsible antibiotic use.

Question 37

What are some new sources for antibiotics being investigated?

Answer 37

Soil microorganisms, crocodile blood, fish slime, honey, and deep-sea organisms.

Question 38

Draw a diagram showing how antibiotic resistance occurs.

Answer 38

1. Population with no antibiotic-resistant bacteria. Action: Chance mutation in one bacterium produces a gene for antibiotic resistance. 2. Population with a few antibiotic-resistant bacteria + Antibiotic A present. Action: Antibiotic A applies a selection pressure - there is a strong natural selection for bacteria with a gene for antibiotic resistance. 3. Population with mainly antibiotic resistant bacteria. Action: Continued selection pressure means almost all bacteria in the population will be antibiotic resistant. 4. Population of almost all antibiotic resistant bacteria.