Section Two Assignment
1. Timeline of the evolution of cells.
• 4.6 Billion years ago: The formation of Earth is believed to have transpired around 4.6 billion years ago.
• 3.5 Billion years ago: Ancient fossils from around this time period provided evidence of a bacteria-like organisms known as Prokaryotes. This ancient cell was first founded in the 1970’s in among fossilized rocks from Australia and contain no nucleus.
• 2 Billion years ago: A more complex prokaryote arises with a skeleton like structure similar to that of blue-green algae. It takes the shape of blue-green chains and is far more developed than a bacteria cell. These newly evolved prokaryotic cells have become capable of photosynthesis, which cause them to release oxygen as a waste product. Photosynthesis also allowed for cells to utilize a much higher amount of energy, producing eighteen times more ATP per sugar molecule than without oxygen, and allowing them to thrive. Evidence of these new cells and the oxygen is releases can be found is fossilized rocks starting from about two billion years ago. Red striped rock layers should signs of high oxygen levels release into the atmosphere. Before this time there were no signs of oxygen within Earth’s atmosphere.
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The Endosymbiotic Theory supports the way eukaryotic cells may have developed. Scientist believe that it began by primitive nucleated cell engulfing masses of blue-green photosynthetic prokaryotes. As same of these prokaryotes survive in the cell, they also begin to make food. The two cells begin to share cell function and become symbiotic. The larger cell provides protection for the smaller cell, while the smaller cell generates food. This is why many single celled organisms contain smaller green cells, such as chloroplasts. This theory is also supported by the fact that certain structures, such as chloroplasts, can function outside of their host cell. This implies that these organisms may have at one time lived independently from their
1. Timeline of the evolution of cells.
• 4.6 Billion years ago: The formation of Earth is believed to have transpired around 4.6 billion years ago.
• 3.5 Billion years ago: Ancient fossils from around this time period provided evidence of a bacteria-like organisms known as Prokaryotes. This ancient cell was first founded in the 1970’s in among fossilized rocks from Australia and contain no nucleus.
• 2 Billion years ago: A more complex prokaryote arises with a skeleton like structure similar to that of blue-green algae. It takes the shape of blue-green chains and is far more developed than a bacteria cell. These newly evolved prokaryotic cells have become capable of photosynthesis, which cause them to release oxygen as a waste product. Photosynthesis also allowed for cells to utilize a much higher amount of energy, producing eighteen times more ATP per sugar molecule than without oxygen, and allowing them to thrive. Evidence of these new cells and the oxygen is releases can be found is fossilized rocks starting from about two billion years ago. Red striped rock layers should signs of high oxygen levels release into the atmosphere. Before this time there were no signs of oxygen within Earth’s atmosphere.
• …show more content…
The Endosymbiotic Theory supports the way eukaryotic cells may have developed. Scientist believe that it began by primitive nucleated cell engulfing masses of blue-green photosynthetic prokaryotes. As same of these prokaryotes survive in the cell, they also begin to make food. The two cells begin to share cell function and become symbiotic. The larger cell provides protection for the smaller cell, while the smaller cell generates food. This is why many single celled organisms contain smaller green cells, such as chloroplasts. This theory is also supported by the fact that certain structures, such as chloroplasts, can function outside of their host cell. This implies that these organisms may have at one time lived independently from their