Could cell structures or RNA have been present before organic molecules existed on Earth? Explain your response.

What is thought to have caused the mass extinction at the end of the cretaceous period?

Heat from earths interior and pressure from overlying rock transform the remains of marine sediments into

Identify characteristics of energy from the sun. check all that apply. almost all of the energy on earth comes from the sun. energy from the sun is known as mechanical energy. the energy in fossil fuels originally came from the sun. plants convert the energy of sunlight into chemical energy.