Despite having a great biodiversity why, is the Amazon Rainforest under risk of desertification?

271

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What are the factors that for influencing photosynthesis also interfere with the gross primary productivity?

303

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What are the typical vegetation and the typical fauna of the tropical forests?

243

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In which type of animals does the placenta exist? What is its main function?

5

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Why can the allantois be considered an adaptation to terrestrial life?

5

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After the blastula stage what is the following stage of the embryonic development? How is the passage from blastula to the next stage called?

5

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What is the function of the vitellus in the vertebrate egg? How are these eggs classified according to the amount of vitellus within them?

5

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What are the animal pole and the vegetal pole of the vertebrate egg?

5

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What are the main substances transferred from the mother to the fetus through the placenta and from the fetus to the mother?

5

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What are the extra embryonic membranes present in vertebrates?

5

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Are the extra embryonic membranes the same in all vertebrates?

5

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Why can the amnion also be considered an adaptation to terrestrial life?

5

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How is the yolk sac formed? What is the function of the yolk sac?

5

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Is there exchange of cells between the mother and the fetus through the placenta?

5

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How is the mesoderm (third germ layer) of triploblastic animals formed?

5

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