6 exam-style questions with full mark schemes and model answers. Write your own answer and the AI examiner marks it against the mark scheme.
Learn this properly: Communicable Diseases and PathogensMonoclonal antibodies are made in the laboratory from a single clone of cells and are all identical, so they bind to one specific antigen. They are produced using hybridoma cells.
Describe how monoclonal antibodies are produced, and explain why a tumour cell is used in the process. (6 marks)
A new antibiotic was tested against a population of bacteria. The table shows the number of live bacteria in a culture before and after 24 hours of treatment.
| Number of live bacteria | |
|---|---|
| Start of treatment | 8.0×106 |
| After 24 hours | 5.0×105 |
(a) Calculate the percentage of the bacteria that were killed during the 24 hours. Show your working. (3 marks)
(b) Antibiotics kill bacteria but have no effect on viruses. State why antibiotics cannot be used to treat viral diseases such as influenza. (1 mark)
Vaccination can protect a person against a disease such as measles.
Describe how a vaccine produces immunity to a disease. (3 marks)
The body has several defence systems that stop pathogens entering and help destroy them once inside.
(a) Describe one way the skin helps to defend the body against pathogens. (1 mark)
(b) White blood cells defend the body once pathogens are inside. Describe two ways in which white blood cells protect the body against pathogens. (2 marks)
Monoclonal antibodies can be used to deliver anti-cancer drugs directly to a tumour. The antibody is attached to a drug and then injected into the patient.
Explain why using a monoclonal antibody to deliver the drug causes fewer side effects than giving the drug on its own. (2 marks)
Measles is a disease caused by a particular type of pathogen.
Name the type of pathogen that causes measles. (1 mark)