<span> cell - A membrane bound structure that is the basic unit of life
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There has been two eons in the Earth's geologic history so far, the Precambrian eon, and the Phanerozoic eon. The eons are the basic and by far longest units on the geological time scale, spreading over hundreds of millions of years.
The Precambrian eon is the eon that starts with the formation of the Earth, up until the development of multi-cellular organisms. A very important event in this eon can be considered the formation of the Earth's oceans, which later enabled the conditions for the development of life. The organisms that dominated this eon are the one cellular organisms.
The Phanerozoic is the eon in which the multi-cellular organisms started to develop and evolve. This eon started with the end of the Precambrian eon, 543 million years ago up until the present. A very important event in this eon is the change of the composition of the atmosphere, which enabled the terrestrial life, as well as the better living conditions for the marine life. It is very hard to choose a dominant form of life in this eon, but worthy of mentioning are the plants, the sinapsids, dinosaurs, mammals, fish.
Answer:
Urey and miller cooked a "primordial soup" with Hadean gases, water and electricity to make <u>glucose</u>, <u>acetic acid</u>, <u>amino acids</u> and <u>lipids</u>.
Explanation:
In the Miller-Urey experiment, the aim was to reproduce the conditions of the earth before the existence of life, with the objective of demonstrating the formation of organic matter from inorganic molecules.
The scientists took water and gases present in the Hadean eon —previous to the existence of life— such as methane, carbon dioxide, hydrogen, nitrogen and even ammonia, the primordial soup. This mixture was subjected to electrical discharges, inside closed containers.
The results were some organic molecules, including glucose, acetic acid, amino acids and fatty acids. In these results the presence of macromolecules, such as proteins or nucleic acids, is not appreciated, however it was a significant contribution to the knowledge of the origin of life on earth.
