You do not need to remember the details on this sheet for your exam but you could be asked to apply your knowledge to unfamiliar situations.
1 Peppered moths can either be speckled or black. Some scientists captured 488 black moths and 496 speckled ones. They placed a small white paint dot on the underneath of each one and let them go in an unpolluted forest. A couple of months later they recaptured moths in the same area. Of the ones with dots on, they found 34 black ones and 62 speckled ones.
a Suggest one reason why not all the moths with dots on were recaptured.
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b Which type of moth seemed to survive better in the forest?
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c Why do you think this type of moth survived better in the forest?
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d Why was the paint put on the underneath of the moth and not the top?
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2 The sentences below are mixed up, but in the right order and describe how modern hedgehogs might have evolved.
¨ The predator avoided eating the mammals with the stiffer hair and ate more of the ones with softer hair. So, the mammals with softer hair died out.
o A new predator entered the area in which the mammal lived.
o Over thousands of years, the mammals with the stiffest hairs were the most likely to survive and gradually this became a species of mammals with spines.
o By chance some of the mammals had stiffer hair than others, which made it more difficult for the predator to eat them.
o Several million years ago a species of mammal had long, thick hair.
a What process is occurring in the first sentence? Circle one process.
environmental variation natural selection evolution adaptation
b Number the boxes to show the order in which the sentences should be read.
© Pearson Education 2010. Edexcel GCSE Science Activity Pack
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