Endosymbiont theory is the idea that eukaryote cells arose in evolution by the fusion of previously free-living protists (prokaryotes). The theory was first suggested by the Russian botanist Mereshkovsky in 1905. The nature of lichens had been worked out; mitochondria and chloroplasts had been seen in cells, and their similarity to bacteria noted. The theory was initially dismissed, but was re-examined when more was known about cell biology.
The eukaryote cell is the type of cell all animals and plants are made of. Some cell organelles, such as mitochondria and chloroplasts, contain DNA. In each case, this DNA is thought to be the remnant of the genome of a once independent bacterium. The theory is that the eukaryote cell evolved by the fusion of several bacteria or archaean organisms. Together, the new cells survived, prospered and evolved into new and complex forms of life. The origin of other organelles in the eukaryotic cell is still under review: the cell nucleus, its membrane, chromosomes and centromeres; the Golgi body; the flagella or cilia; the intracellular membranes. Some of these may also have had a symbiotic origin.
Examples:
There is evidence that symbiosis happened between ancient bacteria to produce the double-membrane class known as gram-negative bacteria. Since the gram-negative bacteria include the cyanobacteria, this was the first of several such events in the history of the eukaryotes.
Four-stroke engine
The four-stroke engine is an internal combustion engine. The four strokes are:
Pecan
The pecan ("Carya illinoinensis") is a species of hickory nut, native to south-central North America, in the United States from southern Iowa, Illinois and Indiana east to western Kentucky, North Carolina and western Tennessee, south through Georgia, Alabama, Mississippi, Louisiana, Texas, Oklahoma and Arkansas; and in Mexico from Coahuila south to Jalisco and Veracruz.
"Pecan" is from an Algonquian word, meaning a nut requiring a stone to crack.
Pecans are often used in cooking in the Southern United States; a common dessert there is pecan pie.
Tariff
A tariff is a tax charged on goods as they pass between one country and another. A tariff can be placed on goods being brought into the country (imports), and goods being exported from the country to another. It is usually done to make money for the government. It may also be done for protectionism. Protectionism makes it easier for local products to sell by making products from foreign countries more expensive.
Often, one government will have an agreement with another not to place any tariffs on goods that are traded between them. This kind of agreement is called free trade.
Klemens Wenzel von Metternich
Klemens Wenzel, Prince von Metternich (German: Klemens Wenzel Nepomuk Lothar, Fürst von Metternich-Winneburg zu Beilstein) (May 15, 1773 – June 11, 1859) was an Austrianpolitician. He is thought of as one of the most important diplomats of all time. Metternich was Foreign Minister for Austria from 1809 to 1848. He got Austria out of a bad treaty with Napoleon, which forced Austria to fight for France. Metternich then helped to build a system in Europe that kept the peace for most of the next 100 years.
In 1809, when Metternich became foreign minister, Napoleon had control of most of Europe. France had taken over some of the closest countries directly. In more distant countries like Austria and Prussia, Napoleon forced them to sign treaties that would make them fight on his side in wars. Metternich thought that was bad for Austria. When Napoleon declared war and raised a huge army for the French invasion of Russia, Metternich told the Russians that Austria would not attack but only defend. Napoleon lost badly in Russia, and Metternich used that excuse to get out of the treaty.
In 1814, troops of the Quadruple Alliance (Prussia, Russia, Austria and the United Kingdom) had entered France, and Napoleon had lost the war. For the next year, diplomats from all over Europe met at the Congress of Vienna to decide the future after Napoleon.
Metternich believed that the best way to keep Europe peaceful was to create a balance of power, with no country being strong enough to beat all the other countries. To make sure that happened, he made some countries stronger so that other countries, especially France, would think twice about going to war. For example, he added Belgium and Luxembourg to the
Netherlands, he turned 300 small countries of Germany into a group of larger countries, and he put together some countries in what we call Italy today.
After making that new order, Metternich also did a lot to keep it together. For example, he Alexander I of Russia Alexander wanted to send troops to Greece to protect Orthodox Christians there fighting the Greek War of Independence against the Ottoman Empire, which was Muslim. The Ottomans had become weak, and Alexander would probably have won. Metternich was afraid that if the Ottoman Empire fell apart, all of the powerful countries in Europe would start fighting to get its land. That would upset Metternich's balance and start a huge war. Also, Russia might get too big and too powerful. Therefore, Metternich convinced the Alexander attacking now would make the Ottomans would fall apart before Alexander was ready to take it for himself, and the United Kingdom and France would get most of it. Alexander agreed to help keep the Ottoman Empire going so that Russia could later take all of it. Also, he was talked out of sending troops to Greece.
Metternich kept peace in Europe for a long time, but there were still some revolts in Europe. Finally in 1848, many revolts happened at the same time. One of them was in Austria, and the rebels had Metternich taken out of office. After he was gone, Otto von Bismarck in Prussia managed to become powerful, take over the German Confederation and start a big German country, which still exists. Having one big Germany, however, upset Metternich's balance and helped to cause World War I.
German Confederation
The German Confederation replaced the Holy Roman Empire in Central Europe. After the Holy Roman Empire fell, Germany had fallen into over 300 different small kingdoms. In 1815, the Congress of Vienna decided that these weak kingdoms were not strong enough to keep France from trying to take them over, which it had already done once under Napoleon. So the Congress combined all those little countries into 39 larger countries, which were still very small compared to the powerful countries of Europe.
The problem was that the Congress did not want to make them too strong, or they'd start taking over other countries. So they put the 39 countries into a confederation which meant that they were all separate countries, but they agreed to help defend each other, and in some ways acted like one big country. The Confederation would not be strong enough to attack another country; only strong enough to preserve the European balance of power.
The German Confederation lasted until 1866, when the members fought each other. The winners formed a new North German Confederation. In 1871 after winning the Franco-Prussian War, Otto von Bismarck, chancellor of Prussia, combined all the countries of Germany into the German Empire.
WrestleMania XXVI
WrestleMania XXIV is the twenty-sixth yearly WrestleMania professional wrestling pay-per-view event put on by World Wrestling Entertainment (WWE). It took place on March 28th, 2010 at the University of Phoenix Stadium in Glendale, Arizona.