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It does not attempt to explain how life originated, but shifts the origin of life to another heavenly body. The advantage is that life is not required to have formed on each planet it occurs on, but rather in a more limited set of locations, or even a single location, and then spread about the galaxy to other star systems via cometary or ...
Crucial to this doctrine are the ideas that life comes from non-life and that no causal agent, such as a parent, is needed. Supposed examples included the seasonal generation of mice and other animals from the mud of the Nile, the emergence of fleas from inanimate matter such as dust, or the appearance of maggots in dead flesh.
Biology is the scientific study of life. [1] [2] [3] It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. [1] [2] [3] For instance, all organisms are composed of at least one cell that processes hereditary information encoded in genes, which
Quizlet is a multi-national American company that provides tools for studying and learning. [1] Quizlet was founded in October 2005 by Andrew Sutherland, who at the time was a 15-year old student, [ 2 ] and released to the public in January 2007. [ 3 ]
In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them underpin biology as a whole.
For example, a test of the ability to add two numbers should include a range of combinations of digits. A test with only one-digit numbers, or only even numbers, would not have good coverage of the content domain. Content related evidence typically involves a subject matter expert (SME) evaluating test items against the test specifications.
The RNA world is a hypothetical stage in the evolutionary history of life on Earth during which self-replicating RNA molecules reproduced before the evolution of DNA and proteins. [27] According to this hypothesis “organisms” emerged when RNA chains began to self-replicate, initiating the three mechanisms of Darwinian selection ...
These can be inorganic (for example, water and metal ions) or organic (for example, the amino acids, which are used to synthesize proteins). [7] The mechanisms used by cells to harness energy from their environment via chemical reactions are known as metabolism. The findings of biochemistry are applied primarily in medicine, nutrition, and ...