ࡱ>   !"#$%&Root EntryZ O2^ZCONTENTS FCompObjVSPELLINGh$>@LN PR''T-V-22889$9h999j::::::::(2"'( ) @S 4"5%4"5% 89h99j:::::" ." "   "  "PS"  TSHTSH " " tt:<:>(ONTTimes New Roman 5dw"@"" " " " " "7` Fvhttp://www.firstscience.com/http://www.youtube.com/http://www.wikipedia.org/w " " " ,,,YSend To OneNote 2007/d,,Letterwpno(winspoolSend To OneNote 2007Send To Microsoft OneNote Port:F"\""V"i"` "`""A."@"\""V"i"` "`"."Essay1.wps"p"p (" (2"'( ) @S  Z O2Quill96 Story Group Class9qy`y` y``+y`7`y``y``Ey`NCHNKWKS FTEXTTEXT8FDPPFDPP<FDPCFDPC>STSHSTSH@STSHSTSH@2SYIDSYIDP@SGP SGP d@INK INK h@BTEPPLC l@BTECPLC @FONTFONT@<TOKNPLC @"STRSPLC A:PRNTWNPR4BFRAMFRAMCTITLTITLiDDOP DOP D(2"'( ) @S 4"5%4"5%Melvin Abreu Essay #1 9.23.10 The Tardigrade is a small aquatic or water dwelling animal. This animal has incredible capabilities that would amaze a normal person. A Tardigrades is also known as a water bear. Water bears have been known to live all over the world, in outer space, and in the oceans. This is an amazing animal, it s a blessing in disguise for the science community. Tardigrades are being explored, studied, and experimented on. The Tardigrade can face many heavy environments and survive. Making it the worlds strongest animal. The Tardigrade looks like a small bear. Its plump and when it walks it wobbles. The Tardigrade is a microscopic invertebrate with eight legs, with a smooth and plump body. It has a tube in its mouth that s called a stylet which helps it pierce through its food to get nutrients. Though they are known for eating vegetation, some are not. Tardigrades also have there own phylum called Tardigrada. They range in length from 0.1 to 1.5mm long; making it very hard to see with the naked eye. They have four segments not including the head, and three to four pairs of legs w/o joints. Each of its feet has four to eight claws. The Cuticle contains Chitin that is moulted periodically. The Tardigrade also appears in the form of a tiny drum or barrel when its in a phase of cryptobiosis; after tucking its legs and head in. The life and lifecycle of a Tardigrade can be pretty interesting. It has many places it can dwell and survive in. Not to mention it lives in the microscopic world where everything is colorful and different. The Tardigrade can be found in sixty-thousand meters high in the Himalayas, four thousand meters deep at the bottom of the ocean, five meters below the surface of Antarctica, or in sand dunes at the equator. But they mostly thrive in damp moss or lichens. They love lakes, ponds, moist patches, stonewalls and roots. The Tardigrade lives for about three to thirty months and can molt about twelve times. There are many different types of species in the class Tardigrada. So they have more than one way to reproduce. Tardigrades are usually oviparous, where there s external fertilization. When a female moults she leaves the eggs inside, which it is then covered in sperm. However, some have internal fertilization, where the female mates before she sheds her cuticle. In most cases the eggs are left inside, but some attach them to the nearby substrate. It takes 14 days to hatch where they live and start the process over again. Tardigrades are the cutest and coolest things to roam the planet. Their like little superheroes that can survive almost anything you throw at them. Tardigrades can be boiled in alcohol, exposed to pressures six times greater than that found on the ocean floor. They can survive the harshest conditions; being exposed to space where there s radiation and space s vacuum. They don t breath, but, there s gas exchanges that take place across the whole of their bodies. Tardigrades are very strong. They are called the toughest and are definitely the strongest. They can survive temperatures from -328 degrees F to 303 degrees F. If you were caught fifty miles downwind from a nuclear blast, the dose of radiation to the body would be 500 Rdgent. 10 Rdgent is lethal to the human body. A Tardigrade can withstand a thousand times that which we can; at an alarming five hundred seventy thousand Rgents. If you were to have no water in the Sierra Desert, you would last 1.5 days where a Tardigrade would survive years. A Scientist happen to awake a Tardigrade found on dried moss in a museum; It was there for 120 years before being found. However, it did die a few days later. They do this by slowing their metabolism down to .01% in a death like state. They turn into tuns, in a state of cryptobiosis. They do this by replacing all the water in their bodies with a sugar called trehelose, this sugar protects their cell membranes from damage for up to 100 years. There are four types of cryptobiosis when faced with a harsh environment. The first is Osmobiosis. This happens when there s a dramatic change in ion concentration in its surroundings, like being dropped in sea water. The next type is Cryobiosis, When encountered with a freezing and thawing environment. Being heated for a few minutes at 151 degrees Celsius and then frozen they managed to survive. They could even stay alive at near absolute zero temperature of -272.8 degrees Celsius. This temperature is colder than that of outer space. At this point there is no free molecule vibration, no metabolism can exist, Therefore, the Tardigrade is  dead . Another type is Anoxybiosis, where there is a lack of oxygen in the air or in the water. This is how they stayed alive for ten days in space. The last type is Anhydrobiosis where they get no water like in a drought. We found that Tardigrades can even live in space. In Sept. 2008 tardigrades were launched into orbit 270km above earth aboard the Russian satellite FOTON-M3. The mission was called TARDIS (Tardigrades in space). They were put in a ventilated container for 10 days and were exposed to the vacuum of space; along with freezing temperatures, weightlessness and extreme dehydration. They also faced high levels of radiation from cosmic rays and solar radiation. Some of them survived and managed to lay eggs that hatched just like the ones on earth. Those that died though, died of radiation destroying their DNA; which is seven hundred to one thousand times than that found here on earth. Tardigrades are useful in the field of science, and in research. Cryptobiosis is being used as a method to preserving sperm, seeds, blood, and food. Japanese use the sugar trehelose to keep a rats heart in a fridge at four degrees Celsius for ten days and then revive it. Doctors today can only keep a human heart alive for up to four hours before transplant. Cryptobiosis being studied for slowing metabolism of passengers on long space journeys to achieve a suspended animation. With more experimentation on this extraordinary animal Scientist will arrive at scientific and medical breakthroughs. In Conclusion, think of getting oxygen through your skin while swimming along underwater. Boiled at high temperatures in alcohol, or floating in space with no space gear to protect you from cosmic rays, and solar radiation that would otherwise bombard skin cells; and because you have this ability it wont rip your DNA apart. You would be able to withstand ice blasts from polar regions, survive years with out drinking water. This is why they call Tardigrades the strongest creatures alive. Tardigrades can even survive after being looked at under an electron microscope. All those free electrons smashing into there bodies is nothing they can t handle. But, with all these things comes a price, the price for immortality is being squished. The tardigrade can still be squashed. That s why scientist look out for when they re under the microscope; a slide can easily squish them. References: FirstScience: Keyword: Tardigrade, 2 Articles. www.firstscience.com Youtube: Keyword: Tardigrade, Video: The water bear (tardigrade), the most extreme animal on our planet. www.youtube.com Wikipedia: Keyword: Tardigrade www.wikipedia.org tellitejourneys A is also ain outer spa space and survive;face . MThought they are nknown for eating fvegetation, some of the are not