- Dec 2022
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bio.libretexts.org bio.libretexts.org
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In the autumn, histones associated with FLC are acetylated, allowing this repressor of flowering genes to be expressed. During winter, enzymes progressive deacetylate FLC, preventing it from being expressed, and therefore allowing flowering genes to respond to other signals that induce flowering. (Origianl-Deyholos-CC:AN)
Example of epigenetic change in plants by season.
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bio.libretexts.org bio.libretexts.org
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Structural Differences and Similarities between Bacteria and Archaea
An glycerol-ether bond in archaea, an glycerol-ester in bacteria and eukaryotes.
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bio.libretexts.org bio.libretexts.org
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American biologist Lynn Margulis developed endosymbiotic theory, which states that eukaryotes may have been a product of one cell engulfing another, one living within another, and evolving over time until the separate cells were no longer recognizable as such.
- Margulis hypothesised the popular classical theory for eukaryotic beginnings.
- Later, as an undergraduate, David Baum proposed the inside-out theory. This is where some eoctye, or archaea, lauched protruding blebs at epibiotic protobacteira. This is how the primitive cell would have harnessed another cell's prokaryotic metabolism for its own benefit, evolving into mitochondria, and in doing so, the inversion of cell membrane into two leaflets via engulfment generates the primitive nucleus -- two layers is still seen.
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- Jan 2022
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bio.libretexts.org bio.libretexts.org
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Prokaryotes were the first inhabitants on Earth, appearing 3.5 to 3.8 billion years ago.
How does this allegation concur to the postulate that eukaryotes were first and prokaryotes were evolved later?
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- Nov 2021
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So to sum things up what caused life's major evolutionary transitions the answer is cooperation major transitions begin when a group of organisms join forces to better survive and reproduce if cooperation continues long enough a new super organism may Emerge one that can then go [on] to reproduce and evolve as a whole and 00:07:42 The pathway that led [to] animals along with humankind [at] least three major transitions have been identified resulting in four layers of Life within your own body
Within this human body, we embed 4 different stages of Major Evolutionary Transitions (MET).
Our human body is the product of billions of years of evolution, embodying various outputs from each major stage of a Major Evolutionary Transition (MET). We are a multi-cellular being, a colony. Yet,at the same time, we have living elements that at one time in history, were independent living beings which were NOT part of a multi-cellular colony!
In the deep history of the evolution of the human body, genes, mitochondria, eukaryotes were all once autonomous living entities, each a biological self with its own boundary separating inner from outer. Virus's helped to catalyze their mutualism over deep time.
Now, over billions of years of evolution, they are all integrated together by the extra-cellular matrix and laminin protein into our multi-cellular human body, replicating as one super, super, super organism.
Finally, inscribed language has allowed us to undergo another kind of transition, a major system transition (MST) where human beings now dominate the entire biosphere, for better and for worse.
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