Biology paper 1, 4.3.1- Communicable diseases.

Describe the cause and symptoms of Measles. [2 marks]

• Cause by measles virus.

• Can cause fever and red skin rash.

Describe the cause and symptoms of HIV. [2 marks]

• Cause by HIV virus.

• Can weaken the immune systems.

Describe the cause and symptoms of Salmonella. [2 marks]

• Caused by Salmonella bacteria.

• Can cause fever and vomiting.

Describe the cause and symptoms of Gonorrhoea. [2 marks]

• Cause by Gonorrhoea bacteria.

• Can cause pain when urinating.

Describe the cause and symptoms of Malarial. [2 marks]

• Cause by Malarial protist.

• Can cause repeating fever.

Describe the life cycle of a malarial. [3 marks]

• Mosquito bites infected person.

• Mosquito has malarial protist.

• Mosquito bites different person and pass malarial protist to them.

Suggest 2 ways we could prevent malarial. [2 marks]

• Use mosquito nets.

• Spray area of still water with insecticide.

Explain how vaccination can can prevent illness.

[3 marks]

• Inject dead pathogen into the body.

• (So), it can stimulate the white blood cells to produce antibodies.

• (So), white blood cells will response and produce correct antibodies rapidly when same pathogen re-enter the body.

Describe the process of discovery and development of medicine. [6 marks]

• Drug usually extracted from plants or microorganisms by chemists.

• Check the toxicity and effectiveness of the drug.

• Preclinical testing- test the drug on tissue/cell/live animals.

• Clinical testing- very dose of drug is given to healthy human.

• If the drug safe, then find the optimal dose of the drug.

• Double blind trials