Practise Viral diseases. 12 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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Measles is a disease caused by a virus. Give two symptoms of measles.
Fever and a red skin rash.
What type of illness does a person usually have soon after being infected with HIV?
A flu-like illness.
Describe how a grower could recognise a tomato plant infected with TMV.
A mosaic pattern of discoloured (pale / yellow) patches on the leaves.
Viruses are much smaller than bacteria. They can only reproduce inside living cells. Measles is a viral disease. Give two symptoms of measles.
Fever and a red skin rash.
Unless it is controlled with drugs, HIV attacks the body's immune cells. What is the name of the late stage of HIV infection, when the immune system is so badly damaged that it can no longer deal with other infections?
AIDS
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
Measles is a disease caused by a virus.
(a) Give two symptoms of measles.[2]
(b) How is the measles virus spread? Tick (✓) one box.[1]
By drinking water containing the virus
By inhaling droplets from coughs and sneezes
By the bite of an infected mosquito
By sexual contact
(c) Most young children in the UK are vaccinated against measles. Give one reason why.[1]
(d) A child with measles was not given antibiotics. Explain why.[1]
Show the answer and mark scheme
(a)Answer: Fever and a red skin rash.
fever / high temperature
red (skin) rash
(b)Answer: By inhaling droplets from coughs and sneezes
(c)Answer: Measles is a serious illness that can be fatal.
measles is a serious illness / measles can be fatal (if complications arise)
(d)Answer: Antibiotics do not kill viruses.
measles is caused by a virus and antibiotics do not kill viruses
Question 2Medium8 marks
HIV is a virus that attacks the body's immune cells.
(a) What type of illness does a person usually have soon after being infected with HIV?[1]
(b) Give two ways that HIV can be spread from one person to another.[2]
(c) Explain why a person with late-stage HIV infection (AIDS) can die from an infection that would not harm a healthy person.[3]
(d) The spread of HIV within the body can be controlled with antiretroviral drugs. Suggest how antiretroviral drugs can stop a person developing AIDS.[2]
Show the answer and mark scheme
(a)Answer: A flu-like illness.
a flu-like illness
(b)Answer: Sexual contact; sharing needles (exchange of blood).
sexual contact / unprotected sex
sharing needles (by drug users)
(other) exchange of body fluids such as blood
(c)
HIV attacks / destroys the immune cells / white blood cells
(so) the immune system is so badly damaged it can no longer deal with other infections
(so) other pathogens are not destroyed and can reproduce / cause serious illness
(d)
(the drugs) stop / slow down the virus reproducing / reduce the amount of virus
(so) fewer immune cells are destroyed / the immune system is not badly damaged
Question 3Hard6 marks
A rapid test for HIV uses monoclonal antibodies. The antibodies bind to a protein that is found only on the surface of HIV.
(a) Explain why the monoclonal antibodies in the test bind to HIV but not to other viruses or to bacteria.[2]
(b) A person who tests positive has not been treated for HIV. Tests show the person has a much lower number of white blood cells than normal. Explain why this person is at greater risk of becoming seriously ill from other infections.[2]
(c) Explain why it is important that people who are infected with HIV are identified as early as possible, even if they have no symptoms.[2]
Show the answer and mark scheme
(a)
monoclonal antibodies are specific to (the shape of) one antigen / one protein
other pathogens have different antigens / proteins on their surface, so the antibodies do not bind to them
(b)
HIV attacks / destroys the body's immune cells (white blood cells)
so the immune system cannot destroy other pathogens, e.g. by phagocytosis or by producing antibodies / cannot deal with other infections
(c)
they can start treatment with antiretroviral drugs early
which stops the virus damaging the immune system / stops AIDS developing
they can take steps to avoid passing HIV on, e.g. using condoms and not sharing needles