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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bWhich type of moth seemed to survive better in the forest?
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cWhy do you think this type of moth survived better in the forest?
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dWhy was the paint put on the underneath of the moth and not the top?
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2The 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.
A new predator entered the area in which the mammal lived.
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.
By chance some of the mammals had stiffer hair than others, which made it more difficult for the predator to eat them.
Several million years ago a species of mammal had long, thick hair.
aWhat process is occurring in the first sentence? Circle one process.
environmental variationnatural selectionevolution adaptation
bNumber 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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