Fig. 7.1 shows bacteria growing on the surface of a dish of nutrient jelly. Paper discs, for example M and N, were first soaked in different antibiotic solutions and then placed on the bacterial growth. A transparent region in the jelly shows that the bacteria there have been killed.
(a)[6]
Use the information above together with your knowledge of natural selection to describe and explain why the jelly around discs M and N looks different.
(b)[4]
Describe how artificial selection differs from natural selection. In your answer, refer to the production of one named economically important plant or animal.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Disc M has a clear zone; disc N shows no clear zone” …