First, DNA and a protein make up chromatin. Then the chromatin is packed up into nucleosomes. Nucleosomes are then packaged up to make a chromosome. The packages do three things: the chromosomes function in cell division; the very long DNA is wrapped up in a shorter package; and the proteins regulate the gene action in cells.
Nucleosomes form the basic repeating units of eukaryotic chromatin. This packs the large eukaryotic genomes into the nucleus and allows it to be controlled.
In mammalian cells about two metres of linear DNA have to be packed into a nucleus of roughly 10 µm diameter. Nucleosomes are folded, in a series of higher order structures, to form a chromosome. This folding compacts the DNA and adds a layer of regulatory control. The control ensures correct gene expression.
Nucleosomes are thought to carry epigenetically inherited information, as modifications of their core histones. This information can be passed on to daughter cells, but it usually wiped out by meiosis in germ cells.
The nucleosome hypothesis proposed by Don and Ada Olins and Roger Kornberg
in 1974, was a big step for understanding eukaryotic gene expression. Kornberg won the Nobel Prize in Chemistry (2006) for this and other discoveries.
Although the nucleosome is a very stable protein-DNA complex, it is not static. It undergoes some structural re-arrangements, such as nucleosome sliding and DNA site exposure. Nucleosomes can inhibit or facilitate transcription.
Since they were discovered in the mid 1960’s, histone changes were thought to affect transcription.
Some modifications have been shown to be correlated with gene silencing, others seem to be correlated with gene activation. The information stored in this way is considered epigenetic: it is not coded in the DNA but is nevertheless inherited by daughter cells. The maintenance of a particular state of a gene is often necessary for cellular differentiation.
Arturo Rodas
Arturo Rodas (born 1954) is a leading Ecuadorian composer. He has lived in London since 1989.
Rodas has composed "24.5 Preludes" for piano; "Climax" for orchestra, "Atonal fugue I" for oboe "d'amore" & piano and electronic music works.
"Since emigrating to England in 1990, he has composed works such as "The Book of the Orchestra",(2002-2003) which is intended to be performed in a house with many rooms so as to allow an “audience” to hear different instrumental groups as they wander from room to room".
Extremophile
An extremophile is an organism (a living thing) which lives best in extreme conditions that are harmful to most life on Earth. They are different from organisms that live in normal places, called "mesophiles" or "neutrophiles".
In the 1980s and 1990s, biologists found that microbes can survive in extreme environments. These are niches that are extreme in some way. They may be extremely hot, or cold, or dry, or under huge pressure, or very salty or acidic. Complex organisms, such as animals or plants, cannot live in these environments.
Some scientists suggest that life may have begun on Earth in hydrothermal vents far below the ocean surface. Environments such as hot oceans, hot springs and deep ocean hydrothermal vents would have been common during the Archaean eon, about 3.9 billion years ago. Early forms of life lived in those conditions.
Most known extremophiles are microbes. The domain Archaea has well-known examples of extremophiles, but some bacteria are also extremophiles. It is a mistake to use the term extremophile for all archaeans, since some of them are mesophilic. Not all extremophiles are unicellular: some extreme environments have animals which are multicellular.
Some extremophiles fall under several categories. For example, organisms living inside hot rocks deep under Earth's surface are both "thermophilic" and "barophilic".
Meowth
Meowth has a cat-like design, with cream-colored fur, and has brown paws and tail tip. It has whiskers, black-and-brown ears, and a gold coin on its head. Meowth is spends most of the daytime sleeping and walks the city streets at night. They put their claws back into their paws so they can move without noise and not leave footprints. Meowth loves round objects, as well as shiny things. The item it loves collecting the most are coins since they are both round "and" shiny. Meowth collects them and keeps them in its nest. Murkrow, a bird Pokémon, also likes coins and steals them from Meowth.
Meowth appears as a wild Pokémon in many versions of the games. Meowth is one of the characters in the Pokémon Mystery Dungeon games. Meowth is also seen in the Nintendo 64 game Pokémon Snap, the Nintendo GameCube game "Pokémon Channel", and many others. Meowth is seen in the Super Smash Bros. series as a Pokémon used with a Poké Ball item, and uses its move "Pay Day" and throws coins at players.
Meowth has made an appearance in almost every episode in the anime because one is owned by Team Rocket agents Jessie and James, the show's main antagonists. He first lived in the city, and tried to impress a female Meowth named Meowzie by learning to walk on two legs and speak human language. Instead of being impressed, she told him he was a freak, so Meowth joined Team Rocket. Meowth was cloned in "", but his clone could not talk or walk on two legs, because Meowth needed to learn how to do this. The Meowth clone is shown again in "". A trainer named Tyson owns a Meowth, which beat Ash's Pikachu a the Hoenn Pokémon League. This Meowth was dressed up like Puss in Boots.
In the Pokémon Adventures manga, Meowth's first appearance is a cameo in the first chapter as one of the Pokémon that escapes from Professor Oak's Laboratory. Meowth has appeared in the Pokémon Trading Card Game first in the Jungle series. A special Meowth card was given when buying the Pokémon Trading Card Video Game. In an open forum interview with ABC News, Pokémon anime director Masakazu Kubo noted Meowth as his favorite Pokémon, saying that while not a major Pokémon in the games, a Meowth is in the anime.
Team Rocket's Meowth ranked fourth on Game Daily's top 10 list of Nintendo characters that deserve their own games, describing him as "adorable" and explaining that his intelligence and ability to speak gave writers more depth than other Pokémon would. IGN stated that without the anime, the character would not have been as famous, further describing it as "probably the funniest part of the show". However, another editor stated it was also popular amongst people who have never seen the anime due to being a feline. IGN also said that Meowth would make a good choice as a playable character in "Super Smash Bros. Brawl" "if Brawl's developers really wanted much more representation for Pokémon as a franchise" also stating "it would be fun to face him in battle as a real fighter, just to be able to send him "blasting off again," referencing Team Rocket's Meowth GamesRadar described Meowth as "not all that useful", and questioned if the Pokémon would have stood out if it were not for its portrayal in the anime.
Seal of Alabama
The Great Seal of the State of Alabama is the state seal of the U.S. state of Alabama. It was designed in 1817 by William Wyatt Bibb, the governor of the "Alabama Territory" and the subsequent first governor of the state. When Alabama became a state in 1819, the state got the design as the official state seal. The seal has a map showing one of the state's most valuable resources—its major rivers. Bibb's design served as the official seal until 1868, when it was replaced by a design having on it an eagle holding in its beak a banner that read "Here We Rest." The legislature and Governor Frank M. Dixon restored Bibb's original design in 1939, and it has remained unchanged since.
Modular origami