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Students investigated how well antibacterial mouthwashes worked.
They tested four different mouthwashes, P, Q, R and S.
They spread bacteria on nutrient jelly in a Petri dish.
They soaked identical discs of filter paper in mouthwashes P, Q, R or S.
They placed the discs on the growing bacteria as shown in Diagram 1.
They incubated the Petri dish for two days.
The nutrient jelly was heated to 120 °C before being poured into the Petri dish.
Tick ( ) one box.
Statement
What is the maximum temperature at which bacteria should be incubated in a Tick ( ) one box.
Temperature
Diagram 2 shows the appearance of the Petri dish after two days.
Which mouthwash, P, Q, R or S kills most bacteria?
Give one reason for your answer.
(Total 4 marks)
A young child goes to school for the first time. Soon after, the child gets a cold and a Explain, as fully as you can, what causes the child’s illness.
The doctor tells the child’s mother that children often get ill when they start school Why is a child more likely to get an infectious illness when he or she starts school? The child gets better without taking any medicine. Explain how.
(Total 4 marks)
The table shows the amounts of carbohydrate, fat and protein in 100 g portions of five How much carbohydrate would the person eat? Describe, in as much detail as you can, what happens to the protein after food A is (Total 5 marks)
Explain, as fully as you can, how the body’s white blood cells respond to Describe, in as much detail you can, how one method of immunisation protects us
How immunisation protects us from this disease.
(Total 7 marks)
Penicillin is an antibiotic which stops bacteria from reproducing. It was used a lot in the past to treat bacterial infections in humans and other animals. In many hospitals thereare now strains of penicillin resistant bacteria.
Explain how natural selection could have produced these strains of penicillin resistant (Total 5 marks)
extra boxes ticked cancels the mark extra boxes ticked cancels the mark digested / broken down / made soluble by protease / enzyme in stomach / in small intestine / from stomach / from pancreasinto amino acids amino acids/smaller molecules/products of digestion absorbed intoblood produce antibodiesproduce antitoxinseffect of antibodies/antitoxins dead/weakened microbes (as appropriate)stimulate antibody productionantibody production rapid if microbe enters again mutation or description of mutation (gives resistance to penicillin) (survivors) reproduce or multiply
asexual reproduction or binary fission or cloning
gene for resistance or the mutation is passed on (to offspring)
allow reference to bacteria being immune ignore reference to survival of fittest

Source: http://hs.eriding.net/download/Teaching_Learning/Science/Core/CORE%20BIOLOGY/HWK%20KEEP%20HEALTHY%20HT%20QUESTIONS.pdf