Which of the following is not a likely reason why life on Earth is carbon based

Which of the following is not a likely reason why life on Earth is carbon based

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Which of the following is not a likely reason why life on Earth is carbon based

Which of the following is not a likely reason why life on Earth is carbon based

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Highlights

There were nine requirements to emerge life on the Earth.

The most probable birthplace of life is nuclear geyser system.

Energy density is the most critical condition for the birth of life.

Abstract

The origin of life on Earth remains enigmatic with diverse models and debates. Here we discuss essential requirements for the first emergence of life on our planet and propose the following nine requirements: (1) an energy source (ionizing radiation and thermal energy); (2) a supply of nutrients (P, K, REE, etc.); (3) a supply of life-constituting major elements; (4) a high concentration of reduced gases such as CH4, HCN and NH3; (5) dry-wet cycles to create membranes and polymerize RNA; (6) a non-toxic aqueous environment; (7) Na-poor water; (8) highly diversified environments, and (9) cyclic conditions, such as day-to-night, hot-to-cold etc.

Based on these nine requirements, we evaluate previously proposed locations for the origin of Earth's life, including: (1) Darwin's “warm little pond”, leading to a “prebiotic soup” for life; (2) panspermia or Neo-panspermia (succession model of panspermia); (3) transportation from/through Mars; (4) a deep-sea hydrothermal system; (5) an on-land subduction-zone hot spring, and (6) a geyser systems driven by a natural nuclear reactor. We conclude that location (6) is the most ideal candidate for the origin point for Earth's life because of its efficiency in continuously supplying both the energy and the necessary materials for life, thereby maintaining the essential “cradle” for its initial development. We also emphasize that falsifiable working hypothesis provides an important tool to evaluate one of the biggest mysteries of the universe – the origin of life.

Keywords

Origin of Earth's life

Nuclear geyser system

Emergence and evolution of life

Falsifiability

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© 2019 China University of Geosciences (Beijing) and Peking University. Production and hosting by Elsevier B.V.

VIDEO: The carbon cycle describes the process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere. Human activities have a tremendous impact on this cycle. Burning fossil fuels, changing land use, and using limestone to make concrete all transfer massive quantities of carbon into the atmosphere. As a result, the amount of carbon dioxide in the atmosphere is rapidly rising — it is now greater than at any time in the last 3.6 million years. Transcript

Which of the following is not a likely reason why life on Earth is carbon based

Blue Carbon

Blue carbon is the term for carbon captured by the world's ocean and coastal ecosystems. Sea grasses, mangroves, salt marshes, and other systems along our coast are very efficient in storing CO2. These areas also absorb and store carbon at a much faster rate than other areas, such as forests, and can continue to do so for millions of years. The carbon found in coastal soil is often thousands of years old. When these systems are damaged or disrupted by human activity, an enormous amount of carbon is emitted back into the atmosphere, contributing to climate change.

Carbon is the foundation of all life on Earth, required to form complex molecules like proteins and DNA. This element is also found in our atmosphere in the form of carbon dioxide (CO2). Carbon helps to regulate the Earth’s temperature, makes all life possible, is a key ingredient in the food that sustains us, and provides a major source of the energy to fuel our global economy.

The carbon cycle describes the process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere. Since our planet and its atmosphere form a closed environment, the amount of carbon in this system does not change. Where the carbon is located — in the atmosphere or on Earth — is constantly in flux.

On Earth, most carbon is stored in rocks and sediments, while the rest is located in the ocean, atmosphere, and in living organisms. These are the reservoirs, or sinks, through which carbon cycles.

Carbon is released back into the atmosphere when organisms die, volcanoes erupt, fires blaze, fossil fuels are burned, and through a variety of other mechanisms.

In the case of the ocean, carbon is continually exchanged between the ocean’s surface waters and the atmosphere, or is stored for long periods of time in the ocean depths.

Humans play a major role in the carbon cycle through activities such as the burning of fossil fuels or land development. As a result, the amount of carbon dioxide in the atmosphere is rapidly rising; it is already considerably greater than at any time in the last 800,000 years.

Video Transcript

What is the carbon cycle? Carbon is the chemical backbone of all life on Earth. All of the carbon we currently have on Earth is the same amount we have always had. When new life is formed, carbon forms key molecules like protein and DNA. It's also found in our atmosphere in the form of carbon dioxide or CO2. The carbon cycle is nature's way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again. Most carbon is stored in rocks and sediments, while the rest is stored in the ocean, atmosphere, and living organisms. These are the reservoirs, or sinks, through which carbon cycles. The ocean is a giant carbon sink that absorbs carbon. Marine organisms from marsh plants to fish, from seaweed to birds, also produce carbon through living and dying. Over millions of years, dead organisms can become fossil fuels. When humans burn these fuels for energy, vast amounts of carbon dioxide are released back into the atmosphere. This excess carbon dioxide changes our climate — increasing global temperatures, causing ocean acidification, and disrupting the planet’s ecosystems.

Which of the following is not a reason why life on Earth is carbon

Initial or the reason for life on earth so based on which the answer to the given question is that carbon can bind to itself is not the reason for the life of life on earth.

Why is life on Earth considered carbon

Life on Earth is based on carbon, likely because each carbon atom can form bonds with up to four other atoms simultaneously. This quality makes carbon well-suited to form the long chains of molecules that serve as the basis for life as we know it, such as proteins and DNA.

Is there any life on earth that is not carbon

On Earth, all known living things have a carbon-based structure and system. Scientists have speculated about the pros and cons of using atoms other than carbon to form the molecular structures necessary for life, but no one has proposed a theory employing such atoms to form all the necessary structures.

Why is life based on carbon and not silicon?

In the case of silicon, the silicon–oxygen bond—the first bond—is so strong that it's very hard to break them apart. This makes the ease and versatility of silicon chemical interactions far lower than the ones involving carbon. This is the reason why carbon is the basis of life and not silicon.