Aqutic Life :: essays research papers

Plants be vituperative to other life on this planet because they form the basis of all(a) food webs. Most plants are autotrophic, creating their own food using piddle, ampere-second paper dioxide, and light through a process called photosynthesis. Some of the earliest fossils fix have been aged at 3.8 billion years. These fossil deposits show present of photosynthesis, so plants, or the plant-like ancestors of plants, have lived on this planet longer that to the highest degree other groups of organisms. At one time, anything that was green and that wasnt an animal was considered to be a plant. Now, what were once considered plants are divided into several kingdoms Protista, Fungi, and Plantae. Most aquatic plants occur in the kingdoms Plantae and Protista.It is believed that the earth was originally an aggregation of patter and swirling gases abtaboo 4.5 billion years ago. The earliest fossil life forms are 3.8 billion years old and contain simple prokaryotic (without a me mbrane-bound nucleus) cells. The atmosphere at that time was mostly nitrogen gas, with large portions of carbon dioxide and water vapour. Since life evolved in this atmosphere, carbon, oxygen, hydrogen, and nitrogen (major elements of nitrogen gas, carbon dioxide and water) authorize up 98% of the thoroughgoing materials in living organisms. There was no oxygen in the early atmosphere, so all life existed in an anaerobic environment.Since no human was alive to document the events of the early earth, overmuch of our information has been pieced together from studies of the fossil record. It is now believed that the earth 4.0 billion years ago was a very tumultuous place there were red electrical storms, radioactive substances emitting large quantities of energy, and molten rock and boiling water erupting from beneath the earths excavate. These forces broke apart the simple gases in the atmosphere, causing them to reorganize into more complex molecules. Ultraviolet light bombarded the surface of the earth, breaking apart the complex molecules and forming new ones. These complex compounds were washed out of the atmosphere by driving rains and subsequently collected in the oceans. umpteen organic molecules tend to clump together, so the early oceans probably had aggregations of organic molecules that looked like droplets of oil in water. These clusters of molecules may have been the ancestors of original cells. They may also have been the source of energy for early life forms primitive cells could have used these complex compounds to satisfy their energy requirements.