Answer:
In the electromagnetic spectrum, the visible spectrum is the part, which is perceptible to the human eye. The electromagnetic spectrum in this array of wavelengths is known as simply light or the visible light. A general human eye will react towards the wavelengths in the range between 380 to 740 nm. A human eye sees the sky as blue that comes in the wavelength 490 nm because of the scattering of the visible light by the particles in the atmosphere. This concludes that 490 nm is the sole wavelength, which is reaching the eye.
1) The answer is <span>bluegreen algae
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Bluegreen algae or cyanobacteria <span>are thought to have started life on earth because they converted the atmosphere that didn't have a lot of oxygen, into an atosphere with enough oxygen to exist life. That </span>oxygen was a product of their photosynthesis.
2) The answer is lightning.
<span>By Primordial Soup Theory, life began as a result of the combination of chemicals from the atmosphere and lighning (a form of energy) to make amino acids. Aminoacids are necessary to build proteins, and proteins are necessary for all the organisms.</span>