FORESTRY
PLANT AND WOOD ANATOMY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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2
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3
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4
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6
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Detailed explanation-1: -There’s nothing magical about the number, yet five digits at the end of their limbs is a motif that runs through all the animals with four limbs, called tetrapods.
Detailed explanation-2: -Why 4 legs? Terrestrial vertebrates have four legs because they evolved from a fish ancestor that had four members that were not too far from actual legs (members that could “easily” evolve into legs). This is what we call a phylogenetic signal.
Detailed explanation-3: -Tetrapods are vertebrates that have, or had, four limbs and include all amphibians, reptiles, birds, and mammals. All tetrapod limbs are made up of similar sets of bones. In some species, such as whales and snakes, some limbs have been lost or radically altered as these animals evolved over time.