Oxygen and Life

Bio Lab 101 Smithsonian Laboratory Early Atmosphere 1. How abundant was type O in the early asynchronous transfer mode? The earths early glory digested only lowly amounts of impoverished oxygen, produced by the reaction of weewee vapor with sunlight. The oxygen rich atmosphere that developed later and on which oxygen breathing bread and butter now depends was result of the origin and spread of organisms up to(p) of photosynthesis. 2. What evidence do scientists draw that the oxygen content of our atmosphere has increase since the earths origin?By looking at the rustiness of antediluvian rocks, scientists attempt to trace the evolution of oxygen in the atmosphere. 3. wherefore is oxygen more abundant in the atmosphere today? spread of organisms that did photosynthesis. 4. What be stromatolites? stramolites ar laminated mound like structures that generally form in modify irrigate through the growth of microscopic blue-green algae and bacteria. 5. What do scientists think is implied by the presence of stromatolites in Precambrian rock?May of the algae and bacteria that build modern stramolites be photosynthesis. 6. What is ozone and how is it produced? Ozone screens out most of the basal violet radiation from the sunlight. Ozone forms through the action of ultra violet radiation on oxygen in the upper atmosphere and many scientist conclude that their layer could take for formed only after oxygen from photosynthesis began to accumulate. 7. Why is the ozone important to life today? The ozone is important to life because it acts as a shield from the harmful effects of direct radiation. . What effect did increased levels of oxygen in the atmosphere have on early life forms? Created a threat because of the early life form because their env bidment polluted by their oxygen reducing neighbors whose internal chemistries could resist oxygen toxic free. bind Iron Formation 1. What is banded iron Rock that contains oxidized iron, iron chemically c ombined with oxygen. 2. When did these formations become common? Formed in antediluvian eld. About 2. 2 billion years agone. 3. What is the significance of these formations?Pebbles and cobbler give that liquid water was present on the surface of the earth, and ion oxides indicate free (uncombined) oxygen was also present, though at very low levels. The Oldest Rocks Remnants of a Youthful ground 1. How old atomic number 18 the oldest rocks on earth? The oldest rocks on earth date prat to 3800 million years ago. 2. What evidence of life do these ancient rocks contain? the presence of oxygen to the activity of oxygen producing organisms, therefore life was far along. 3. Is this evidence great enough to consent to scientists to conclude that life indeed existed during this period?No because the physical processes in the atmosphere could also have produced free oxygen and in many rocks residues that contain carbon have a make up uniform to subsisting matter but these residues to may have purely chemical origin. The Earliest Traces of Life 1. When do scientists think life originated on Earth? Between 4600 million years ago to 3500 million years ago. 2. What are the oldest fossils and how old are they? The oldest fossils on record are stromatolites, which date patronise to 3500 million years ago. The Precambrian 1.When did the first cells with nuclei appear? 3800 million years ago 2. Fossils of multicellular animals are from what time period? The fossils of multicellular animals date back to the Precambrian time period. 3. In what era did all of these sluicets take place? The events listed above took place at the beginning of the Cambrian period to the end of the Paleozoic era. Origin of Life 1. What genes are most prevalent in living organisms? The six elements most prevalent in living organisms are carbon, hydrogen, nitrogen, oxygen, phosphoric and sulfur. . Were these elements present in the infant solar transcription? The only element out of the s ix listed above that was present in the infant solar system was hydrogen. It also had helium. 3. What circumstances may have fostered the development of durance of amino acids and nucleotides? The circumstances that may have played a class in the development of these chains were the conditions in which they were formed. They formed in small ponds that periodically heated and dried, leaving traces of these water molecules that would play a recrudesce in producing the chains. . What are the characteristics of the ancestors of living cells and what could they do? The ancestors of living cells, also know as the forerunners, were single celled, with a ring shaped coil of DNA. They would piece into clumps, absorb smaller molecules, rearrange them, and released them as waste products. 5. Why is water important to life? Water is the medium in which biochemical reactions occur, contend an extreme importance in creating and sustaining life here on earth. 6. What are the true hallmarks of life? omplicated network of energy producing an energy consuming reactions incontrovertible the ability of the entire system plus the ability of the entire system to produce itself was the hallmark of true life. 7. What molecular evidence do scientists have that all life is at least distantly related and has a common ancestor? The possible varieties of proteins are virtually unlimited even for the primitive proteins life ferredoxin. If one calculates the possible combinations of percent amino acids along a ferredoxin chain of fifty four links the result is a number more potential variations than there are atoms in the cognise universe.Drspite the vast possibilities portions of amino acids sequences are similar or even homogeneous in proteins from organisms as dissimilar as humans being and bacteria. Since it is incredible that this could occur by chance, scientist interpret this to mean that all life is at least distantly related and shares common origin. 9. What conditions are thought to have existed on primitive earth that favored the origin of life? The conditions on primitive earth that favored the origin of life included an atmosphere rich in carbon dioxide and water vapor.Also, hot springs and small bodies of water formed the chemical building blocks of life. Single Celled Life 1. What are cherts? Cherts are sedimentary rocks that are fine grained, silica rich microcrystalline, cryptocrystalline, or micro-fiborous that contain fossils. 2. How old are these fossils? The fossils within cherts are between 2100 and 1800 million years old. 3. Were these prokaryotic or eucaryotic? These fossils within cherts are prokaryotic. 4. What evidence for eucaryotic (and possibly multicellular) life is found in the Greyson shale?The evidence for multicellular/eukaryotic life within the Greyson shale is found in the dark features of a samples surface. They are large, organized, and in a spiral shape, which represent the characteristics left behind of a eukaryotic organism. 5. How old is the shale? The shale is 1300 million years old. Multi-celled Life 1. Describe the Ediacaran sentient being Fossils of soft bodied organisms that lived mre than 570 million years ago occur in the sandstone deposit on the edicora hills of South Australia. 2. How old are these fossils? The fossils within the Ediacara living organism are 570-670 million years old.