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Biology chapter 14 origins of life
Biology chapter 14 origins of life
Chapter 13 earth systems volcanoes
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The Origin of Eukaryotic Cells
In the beginning of the creation of Earth volcanoes erupted all over the planet. During this period there was a time where a brief cooling period was allowed to take place. When this period took place evaporation caused a downpour of rain which flooded the ocean creating the ocean. At the time that ocean was averaged at 3,000 degrees Fahrenheit. Around this same time an asteroid so powerful hit the Earth knocking off a large chunk of it. This chunk became the moon which at the time was twice as close as it is today. The hitting of the planet Earth cause such a shake that many new undersea volcanoes began spewing forth molten rock and gasses. These gasses and other particles formed on the oceans surface and with the moon being so close were smashed together by strong and violent waves.
Molecules were then washed ashore and exposed to heat and sunlight. Through a series of trial and error bases chemical reactions formed cells. The first ones were simple only with the new permeable membrane so it could absorb nutrients. After absorbing so many amino acids it was able to replicate itself. Bacteria now was growing off the undersea volcanoes vents living off of hydrogen sulfide. Some of these developed hard shells and others with soft membranes. Meanwhile tectonic plates during this time were shifting drastically and created mountain ranges which altered rain patterns and led to the falling of even more rain which created rivers. These rivers washed out new nutrients found in land out to the oceans. Minerals from land reacted with carbon dioxide which resulted in the production of oxygen. As temperatures cooled algae created glucose through photosynthesis and released gross amounts of oxygen into the ocean. The oxygen reacted with the metallic ions found in the ocean and cause oxidation which caused the sea to turn a rusty red.
The sea then turned back to a royal blue now rich w/ oxygen but to the bacteria oxygen was a toxin. The soft membrane bacteria learned to live avoiding oxygen and the hard shelled bacteria created enzymes to prevent damage caused by oxygen.
There are many different cells that do many different things. But all of these cells fall into two categories: prokaryotic and eukaryotic cells. Eukaryotic cells contain a nucleus and are larger in size than prokaryotic cells. Prokaryotic cells do not contain a nucleus, are smaller and simpler than eukaryotic cells. Two of their similarities are they both have DNA as their genetic material and are covered by a cell membrane. Two main differences between these two cells are age and structure. It is believed that prokaryotic cells were the first forms on earth. They are considered primitive and originated approximately 3.5 billion years ago. Eukaryotic cells have only been around for about a billion years. There is strong evidence that suggests eukaryotic cells may be evolved from groups of prokaryotic cells that became interdependent on each other (Phenotypic analysis. (n.d.).
Eukaryotic Cells are Deemed as a Result of the Evolution of Symbiotic Prokaryotes Both Prokaryotic and Eukaryotic cells over time have sustained very dynamic changes from one another. More specifically we have seen the appearance of a more complicated and organized cell structure, the nucleus. However the big question amongst scientists today is how did these changes first occur? A fundamental concept of this evolution is the belief in the natural progression 'from the simple, to the more complex.' However one popular theory that argues that Prokaryotic symbiosis was responsible for forming the Eukaryotic nucleus is the 'Endosymbiotic Theory' this theory was first proposed by a former Boston University Biologist known as Lynn Margulis in the 1960's.
Basalt forms due to the partial melting of the layer of the mantle called the asthenosphere. The asthenosphere is the plastic zone of the mantle beneath the rigid lithosphere. Mantle plumes coming from the mesosphere can cause the asthenosphere to melt with heat or even if pressure decreases, which is called decompression melting (Richard 2011). The magma that forms from this melting is mafic magma that solidifies once it reaches the earth’s surface and cools quickly. The above process mainly occurs mainly during intraplate igneous activity which is the main explanation for volcanic activity that occurs a long distance away from a plate boundary. If the tectonic plate above the mantle plume is moving it can create a string of volcanic activity such as in Hawaii. See Fig 2.
The Precambrian Era is when the Earth formed. Earth was barley a spec of dust in outer space and as time went by it gathered ice, rock and more dust particles. It eventually formed into a big rock flying around in space. The Earth was extremely hot and so when it rained the rain would evaporate in mid air or immediately after it hit the ground. But even though it evaporated these great rains cooled the Earth eventually building up water in lower areas creating oceans. The Earths atmosphere was water vapor, carbon dioxide, nitrogen and gases. After awhile oxygen level grew in the atmosphere. The earliest life forms were single celled organisms that lived in the oceans. These organisms used light energy to produce food called photosynthesis. These were called Prokaryotes and Eukaryotes. The evolution of multi celled organisms were Dramatic in change.
There are two main types of cells in the world. The simplest cells such as bacteria are known as Prokaryotic cells, and human cells are known as Eukaryotic cells. The main difference between each of these cells is that a eukaryotic cell has a nucleus and a membrane bound section in which the cell holds the main DNA which are building blocks of life.
...tioned. What caused the tidal wave is still a mystery, although many people believe it was caused by volcanic eruption, or a large meteorite crashing into the Earth’s surface.
The major composition of the ocean chemistry that is affected by atmospheric CO2 are understood for the most part and can be calculated accurately. However there is much uncertainty of the biological effects caused by ocean acidification and how it will vary amongst organisms; some may cope better than others. Even though the research on ocean acidification is still very young, there is already evidence of biological impacts due to changes in the chemistry of the ocean. The greatest evidence of the impactions of ocean acidification on marine ecosystems can be seen in experiments on calcifying organisms. When seawater is acidified to various amounts the formation and dissolution of calcium carbonate shells and skeletons in marine organisms such as reef-building corals, oysters and mussels, and phytoplankton and zooplankton which for the base for marine food webs (“Ocean Acidification: A National Strategy…”,
The moon is by far the biggest and most easily recognizable object in earth’s atmosphere that can be perceived by the naked eye on a cloudless night. It is hypothesized that it came into existence nearly 4.5 billion years ago, from residual debris after a planetary body collided with earth. Although, considered the runner-up to the sun as the second brightest object in the sky, its illumination is deceitful, insomuch as the moon is not a source of light, but instead reflects the sun’s illumination from the half of the moon that is in direct alignment with the sun at that time. More readily identified as a satellite of the earth rather than as a planet itself or even a star, it has a diameter a quarter of the size of earth’s size and it lacks an atmosphere, although date suggests a possibility that water may exist in the form of ice some embedded in craters near it’s North and South Pole. Similar to earth the moon posses a crust, mantle and core and is composed of comparable minerals such as oxygen, silicone, magnesium, aluminum, etc…
There are several theories about how the Cambrian Explosion started. There were major changes in marine environments and chemistry from the late Precambrian into the Cambrian, and these also may have impacted the rise of mineralized skeletons among previously soft-bodied organisms. One theory as to what happened is that oxygen in the atmosphere, with the contribution of photosy...
There are five basic theories in the formation of our moon. The first is the "fission theory" which states that the moon was once a part of earth, but separated a long time ago. The second theory is called the "capture theory". This theory is says that the moon formed somewhere else, and was "captured" by earths gravitational pull. The third theory is called the "condensation theory" this theory states that the moon and earth were condemned together from the original nebula that formed our solar system. The fourth theory called the "Colliding Planetesimals Theory" states that the interaction between the earth orbiting the sun, and the sun orbiting planetesimals, which are large Astroid like rocks, led to the breakup and formation of our moon from the debris of these planetesimals. The fifth and final theory is called ...
...lieve that millions of years ago, a piece of rock as big as Mars hit the Earth, and the collision blasted a huge amount of rock into space, and the shattered pieces of rock went into orbit around the Earth. Over millions of years, the rocks clumped together to form the moon, and now it is not the pieces of rock that orbit the Earth, but the moon itself. Scientists, Native Americans, and many other people have their theories of how the moon became, but none have been proven. Scientists have studied the moon for many years, and have proven many theories, but not this one.
The gravitational forces between the Earth and the moon cause some interesting effects; tides are the most obvious. The moon has no atmosphere, but there is evidence by the United States Department of Defense Clementine spacecraft shows that there maybe water ice in some deep craters near the moon's North and South Pole that are permanently shaded. Most of the moon's surface is covered with regolith, which is a mixture of fine dust and rocky debris produced by meteor impact. There are two types of terrain on the moon. One is the heavily cratered and very old highlands. The other is the relatively smooth and younger craters that were flooded with molten lava.
The interior structure of the earth is made up of crust, the mantle and core (inner core and outer core). Earthquakes occur on the crust. Crust forms the external layer of the earth surface. On the crust, the plate tectonics forces are in charge of causing the abrupt earth movements. Due to the existence of an immense temperature and concurrent pressure difference in the outer layer and inner layer of the earth, convection currents occur at the mantle. This energy results from overwhelming decomposition of radioactive substances contained by the rocks found at the interior of the earth. The developed convection currents lead to movement of lava; cold lava finds its way to the interior of the earth crust, while the molten lava which is generally hot, leaves the interior of the earth to the outside of the earth crust. These kinds of circulations occur at different locations of the earth surface and consequently results in segmentation of the earth due to movement in different directions.
How life arose is a question that is fundamental to both philosophy and science. Responses to it enable one, in turn, to answer such questions as, “Who am I?”, “Why am I here?”, and “How do I make sense of this world?” This secondary set of questions can be answered in a myriad of ways for a variety of reasons, but the answer to the first question has only two responses. As Douglas Futuyuma says, “Creation and evolution, between them, exhaust the possible explanations for the origin of living things” (197). Either we are the product of the chemical and physical laws of nature operating over time, or we have been formed, at least in part, by some supernatural Force or Deity. The acceptance of one of these options as a foundation will determine how one will establish a belief system to determine his place in the world. This is a matter of crucial importance, yet in most biology classes offered at U.C. Davis, we learn that life came from nonlife by strictly natural (as opposed to supernatural) processes. The possibility that perhaps the origin of life cannot be explained by a natural mechanism is ignored, and this is disturbing. For if we limit what explanations we are willing to accept for the origin of life, we could be closing our eyes to reality.