OBJECTIVE LIFE SCIENCE
EVOLUTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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a shared ancestral character
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a shared derived character
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a character useful for distinguishing birds from mammals
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an example of analogy rather than homology
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Detailed explanation-1: -As the character of four limbs (tetrapod condition) is shared among the classes and is also present in their ancestral organism, it is a shared ancestral character. Thus, four limbs are a shared ancestral character because they are found in mammals and birds along with their ancestors.
Detailed explanation-2: -Answer and Explanation: In a comparison of birds and mammals, having four limbs is a shared ancestral character. This common ancestor (the clade amniotes) existed 310-330 million years ago.
Detailed explanation-3: -But a study published Friday suggests that they all evolved from a common ancestor some 320 million years ago. This ancient reptilian creature-which gave rise to dinosaurs, birds and mammals-is thought to have been covered in scale-like structures.
Detailed explanation-4: -(d) Homeothermy (warm blooded) is a common feature shared both by birds and mammals.
Detailed explanation-5: -Derived Characters Four limbs, for example, is a derived character for the clade tetrapoda. Hair is a derived character for the clade Mammalia, but four limbs is not derived for mammals. If it were, only mammals would have four limbs!