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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Ducks live together in groups
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Tree frogs change color to hide in the forest
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Birds have hollow bones that help them fly
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Bears have thick fur to protect them in cold weather
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Detailed explanation-1: -Instead of heavy jaws and teeth, they have lightweight beaks. And instead of fur, they have feathers. These are light, streamlined and cleverly adjustable for flight control. Their bones are also hollow (pneumatised) making them lighter for flight.
Detailed explanation-2: -In order to attain the lift necessary for flight, birds have evolved a number of modifications to their skeletal system, including pneumatic, or hollow bones, and reduction of the number of bones by loss or fusion. Hollow, air-filled bones lighten the weight of the skeleton.
Detailed explanation-3: -Birds have light and hollow bones. Most birds are capable of flight with the help of these bones. These hollow bones make their body light which allows them to lift themselves easily.
Detailed explanation-4: -Answer and Explanation: Birds are able to fly as a result of structural adaptations such as a light skeleton due to hollow bones, strong chest muscles that allow wings to beat, and wings instead of front legs. For birds to be able to fly successfully, they must have light bodies combined with strong muscles.