The various of living things
Now days scientists have found and described approximately 1.75 million species on Earth. Plus, new species are being discovered every day. From tiny bacteria to yeasts to starfish to blue whales, life's diversity is truly impressive! One way to make sense of it is by classification. Scientists put similar species into groups so that those millions of species do not seem so overwhelming. People rely on their knowledge of classification to understand what different species are like. You may have done this without even thinking about it! For instance, let’s say that a friend of yours tells you that he saw an egret last weekend. You have never heard of an egret before, but if he tells you that an egret is a type of bird, you should have some idea of what it is like. Living things are divided into three groups based on their genetic similarity. The three groups are: Archeae,Eubacteria and Eukaryota. Archaea are microbes. Most live in extreme environments. These are called extremophiles. Other Archaea species are not extremophiles and live in ordinary temperatures and salinities. Some even live in our guts! Some extremophile species love the heat! They like to live in boiling water, like the geysers , and inside volcanoes. They like the heat so much that it has earned the nickname "thermophile", which means "loving heat", and it would probably freeze to death at ordinary room temperature. Other extremophile Archaea love to live in very salty, called hypersaline, environments. They are able to survive in these extreme places where other organisms cannot. These salt-loving Archaea are called halophyles. Eubacteria, also known as “true bacteria”, are microscopic prokaryotic cells. Cyanobacteria, also called blue-green algae, are Eubacteria that have been living on our planet for over 3 billion years. Blue-green algae grow in the shallow parts of the ocean. Today it is only common in certain regions, but a few billion years ago, there was...
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