The various planets are thought to have formed from the solar nebula, the disc-shaped cloud of gas and dust left over from the Sun's formation.
The study of distribution of living organism is kow as demography, while studying their fosils is known as paleantology.
1.Fertilization occurs when sperm fuses with egg.
2.Bacteria
Just took the test and they were both correct.
Answer:
older rock would have returned to the mantle through subduction
Explanation:
The reason why the ocean floor is only 180 million years old even though the oceans exist much longer then that on Earth, is because of the movement of the tectonic plates, a process through which the oceanic plates are getting subducted and melted into the mantle. The oceans that have existed prior to the ones that exist today haven't really left significant traces of their crust behind them. The reason for this is that the oceanic plates over which these oceans were got below the continental plates, thus got subducted. As they got subducted, they got destroyed in the mantle. The oceanic crust that we have nowadays is only 180 million years old, but as the time passes, the older oceanic crust will face the same destiny, and there will constantly be new one replacing it.
