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There are different types of nerves. Some of them are sensory nerves like the ones in your hands and feet, and some complete other functions. However, they all originate from somewhere.
Cranial nerves originate from the brain itself, and spinal nerves come from the spinal cord. Damaging any can cause serious injury like death and paralysis. There are 12 cranial nerves in the nervous system, and 10 out of 12 originate in the brain stem.
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Vestigial structures are often homologous to structures that are functioning normally in other species. Therefore, vestigial structures can be considered the evidence for evolution, the process by which beneficial heritable traits arise in populations over an extended period of time.
Decomposers, as the name suggests, decompose dead plants or animals into simple compounds. They feed on dead producers from the first levels or consumers from other three levels. Breaking them down, decomposers release nutrients that producers can use.
In an ecosystem with four levels, the first level are producers, such as plants and algae. On the second trophic level, there are primary consumers, herbivores that eat plants, for example, a deer, a rabbit, a grasshopper. The next trophic level belongs to secondary consumers that eat herbivores, for example, a wolf, a fox. The highest level is tertiary consumers that eat carnivores, for example, a bear, an eagle.
Answer:
gases of nitrogen and many more