- Define and explain A Healthy Lifestyle in your own words
- Use key terms such as pathogen accurately
- Apply what you have learned to new examples and questions
- Avoid the common mistakes learners make with this topic
This lesson focuses on A Healthy Lifestyle: explore how diet, exercise, sleep and avoiding smoking protect long-term health.
Explore how diet, exercise, sleep and avoiding smoking protect long-term health.
Key ideas
Vaccines and lifestyle
A vaccine introduces a harmless form of a pathogen so the immune system makes memory cells without the person suffering the disease. If the real pathogen later arrives, the response is rapid. Beyond immunity, health depends on lifestyle: a balanced diet, regular exercise, enough sleep, and avoiding smoking and excess alcohol all reduce the risk of heart disease, type 2 diabetes and some cancers.
Types of pathogen
Bacteria are single-celled organisms; some cause disease by releasing toxins. Viruses are far smaller and can only reproduce inside living cells, damaging them. Fungi such as athlete's foot thrive on skin, while protists such as the malaria parasite are spread by vectors like mosquitoes. Knowing the type matters because treatments differ: antibiotics kill bacteria but do nothing against viruses.
Key term — pathogen: A microorganism that causes disease, including some bacteria, viruses, fungi and protists.
Give three lifestyle choices that reduce the risk of heart disease.
Any three of: eating a balanced diet low in saturated fat and salt; taking regular exercise; not smoking; limiting alcohol; maintaining a healthy weight.
Answer: Any three of: eating a balanced diet low in saturated fat and salt; taking regular exercise; not smoking; limiting alcohol; maintaining a healthy weight.
- Believing 'natural' means safe Many natural substances are harmful — tobacco smoke and alcohol are natural in origin yet damage health. What matters is the evidence of harm, not whether something is natural.
- Taking antibiotics for a cold or flu Colds and flu are caused by viruses, and antibiotics only kill bacteria. Using them unnecessarily also encourages antibiotic resistance.
Practice
The vaccine triggers an immune response that produces memory lymphocytes. If the real pathogen later invades, these memory cells mount a rapid response before the person becomes ill.
Bacteria – e.g. food poisoning or tuberculosis; viruses – e.g. flu or measles; fungi – e.g. athlete's foot; protists – e.g. malaria.
Antibiotics target structures and processes found in bacterial cells, such as cell walls. Viruses lack these structures and reproduce inside human cells, so antibiotics cannot attack them.
A phagocyte is a white blood cell that engulfs pathogens and digests them with enzymes, destroying the invaders.
Quick check
Which of these best defines "pathogen"?
Give two barriers that stop pathogens entering the body.
- A Healthy Lifestyle: explore how diet, exercise, sleep and avoiding smoking protect long-term health.
- Vaccines and lifestyle: A vaccine introduces a harmless form of a pathogen so the immune system makes memory cells without the person suffering the disease.
- antibody: A Y-shaped protein made by white blood cells that locks onto a specific antigen on a pathogen, marking it for destruction.
- Watch out for: believing 'natural' means safe