The predominant hypothesis for why the animals needed some 3 billion years to evolve after the life first appeared on the planet is that the conditions were not right for them to appear.
The life on Earth has appeared much earlier that what we normally assume, and also it has not been evolving very quickly, but instead it has been a very slow and gradual process. The reason for that is that the living conditions on the Earth were much different than what are they now, or anytime from the Cambrian period until the present.
The surface was still pretty hot, and there was intense volcanic activity. The composition of the atmosphere was not suitable for animals to appear at all, and in fact it would have been toxic for them. The water too had chemicals in it that were not providing the right conditions for animals to evolve. It was only after the plants started to appear and managed to make lot of changes in the water, atmosphere, and land, than the animals were able to evolve and develop.
Only one sound blocking material should tested at once and the sound will vary on how much and what kind of materail you use.
Answer:
Flagellum plant or animal
Flagella are tail- or whip-like structures that protrude from some animal cells. The most familiar example is probably the exceptionally long flagellum found on sperm cells. By lashing to and fro, the flagellum drives the cell forward and powers its motion.
Explanation:
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Coal is the most-used fossil fuel for energy production in the United States. This is controversial because although coal is abundant, it is one of the worst pollutants.
