EVOLUTION
SOURCES OF VARIATION IN A POPULATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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an adaptation
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environment
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response
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stimulus
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Detailed explanation-1: -A giraffe’s long neck is an adaptation that helps the giraffe reach foods that other animals can’t eat, such as leaves that are very high up in trees.
Detailed explanation-2: -They are the world’s tallest mammals. They are uniquely adapted to reach vegetation inaccessible to other herbivores. Unusually elastic blood vessels and uniquely adapted valves help offset the sudden buildup of blood (to prevent fainting) when giraffes’ heads are raised, lowered, or swung quickly.
Detailed explanation-3: -This is ‘natural selection’. Consider the giraffe, for example. A Darwinian theory of evolution posits that it was through random variation that some giraffes had longer necks than others. Thanks to their long necks, they were able to reach leaves high up in the trees in their environment.