* A balanced diet is one that contains carbohydrates, proteins, fats, mineral ions and vitamins vital for keeping healthy.

* Someone who doesn’t have a balanced diet is malnourished.

* Exercise increases the rate at which cells release energy (a process known as respiration).

* Two main types of microorganism that cause disease in the body (pathogens) are bacteria and viruses.

* The immune system is how the body defends itself against pathogens.

* Semmelweiss realised that washing hands could help prevent infections spreading.

* White blood cells can produce antibodies which attack specific pathogens.

* Antibiotics kill bacterial infections.

* An antibiotic resistant strain is one which is not killed by antibiotics.

* Vaccinations involve injecting a small amount of dead or inactivated pathogen into the body so that it can produce the antibodies in advance of getting the real infection.

* Uncontaminated cultures of microorganisms can be used to investigate antibiotics.

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Test it!

1. A balanced diet is important for health. Cells in the body only need a little:

a) protein

b) vitamins

c) carbohydrates

2. Influenza is an infectious disease and outbreaks can be very serious. Describe how a mutation of this virus could make an outbreak worse?

3. Being obese can lead to Type 2 diabetes. Name another two health conditions that being overweight can cause.

i. ____________________________________________

ii. ____________________________________________

4. How did Semmelweiss help save thousands of lives?

5. Vaccines are a good way to protect people against viral diseases. Complete the sentences.

a) Viruses are harder to kill than bacteria because ____________________

b) The virus in a vaccination is either _______________ or _______________

c) A vaccine works by stimulating white blood cells to release _______________

ANSWERS

1. b) vitamins

2. Through mutation influenza is able to produce a new strain. The new one could mean that antibiotics and vaccinations will have no effect on it which could then cause an outbreak as people are no longer immune and there’s no treatment to deal with it.

3. Being obese can also lead to heart disease and cancer.

4. He realised that certain infectious diseases could be easily passed from patient to patient due to the fact that doctors didn’t wash their hands. Therefore, he insisted that hand-washing should be carried out before patient examinations thereby substantially diminishing the number of people dying from these infectious diseases.

a) …the attack the body from inside the cells.

b) …dead or inactivated pathogens.

c) …antibodies