Answer:
...it is necessary for life.
Explanation:
continues to exist on the surface of Earth because the planet is at a distance far enough from the Sun that it does not lose its water to the runaway greenhouse effect, but not so far that low temperatures cause all water on the planet to freeze.
Answer: RNA is a more stable molecule than DNA
Explanation: DNA (deoxyribonucleic acid) is much stable than RNA (ribonucleic acid) for many reasons; Frist of all its because of the double strand of the DNA versus the single-stranded RNA. This is thanks to the Hydrogen bonding between bases since those bondings release free energy that allows the molecule to be provided by more thermodynamic stability.
Also the lack of 2′ OH groups makes DNA more stable since the OH groups are very reactive by themselves. In the DNA sugar molecule there is not a spare OH group that could start reacting on its own. So this is why DNA is immune to chemical reactions, while RNA (having an extra OH group) is more chemically "promiscuous".
Answer: Plants, from their roots, suck up nitrogen compounds. These compounds are obtained by animals as they consume plants. The nitrogen compounds in the organic matter re-enter the soil when plants and animals die or when animals excrete waste, where they are broken down by microorganisms, called decomposers.