Largest bacterium ever discovered has an unexpectedly complex cell
Giant microbe from a mangrove could be a missing link between single-celled organisms and the cells that make up humans
By definition, microbes are supposed to be so small they can only be seen with a microscope. But a newly described bacterium living in Caribbean mangroves never got that memo (see video, above). Its threadlike single cell is visible to the naked eye, growing up to 2 centimetersâ€”as long as a peanutâ€”and 5000 times bigger than many other microbes. Whatâ€™s more, this giant has a huge genome thatâ€™s not free floating inside the cell as in other bacteria, but is instead encased in a membrane, an innovation characteristic of much more complex cells, like those in the human body.
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Robot made of magnetic slime could grab objects inside your body
Slime that can be controlled by a magnetic field can navigate tight spaces and grasp objects, making it ideal for possible uses inside the body
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Li Zhang at the Chinese University of Hong Kong and his colleagues mixed neodymium magnet particles with borax, a common household detergent, and polyvinyl alcohol, a kind of resin, to form a slime that can be controlled
All of the bases in DNA and RNA have now been found in meteorites
The discovery adds to evidence that suggests life’s precursors came from space
More of the ingredients for life have been found in meteorites.
Space rocks that fell to Earth within the last century contain the five bases that store information in DNA and RNA, scientists report April 26 in Nature Communications.
These “nucleobases” — adenine, guanine, cytosine, thymine and uracil — combine with sugars and phosphates to make up the genetic code of all life on Earth. Whether these basic ingredients for life first came from space or instead formed in a warm soup of earthly chemistry is still not known (SN: 9/24/20). But the discovery adds to evidence that suggests life’s precursors originally came from space, the researchers say.
Scientists have detected bits of adenine, guanine and other organic compounds in meteorites since the 1960s (SN: 8/10/11, SN: 12/4/20). Researchers have also seen hints of uracil, but cytosine and thymine remained elusive, until now.
“We’ve completed the set of all the bases found in DNA and RNA and life on Earth, and they’re present in meteorites,” says astrochemist Daniel Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Md.
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At first when I saw the equation, I thought she was proposing to stop the entropy from growing. :lol:The Closest We Have to a Theory of Everything: