Answer:
True
Explanation:
Precambrian, period of time extending from about 4.6 billion years ago (the point at which Earth began to form) to the beginning of the Cambrian Period, 541 million years ago. ... The Precambrian represents more than 80 percent of the total geologic record.
What do you mean <span>It has been observed that certain species of insects which had not previously caused significant harm have become serious pests. the best explanation for this phenomenon is that the pesticide killed off predators which had previously held this species in check. a mutation occurred in the species. the pesticide increased the vigor of the species. was able to be used by the pest as an additional food source is also a reproductive for some insect species. </span><span />
Natural changed to the ecosystem relate to environmental shock that occur naturally. Natural changes include floods, volcanic activity, hurricanes, etc. They can be destructive, but they also have advantages. Floods have the contribution of nutrients to the soil which was lacking. It can also relocate fishes and organisms living in bodies of water which improves the ecosystem.
Sensory" Neuron
"Associative Neuron"
"Motor" Neuron
