How Pearls Form and Which Species Makes Them

The pearls you may wear in earrings and necklaces are the result of an irritant under the shell of a living organism. Pearls are formed by saltwater or freshwater  mollusks—a diverse group of animals that includes oysters, mussels, clams, conchs, and gastropods. How Do Mollusks Make Pearls? Pearls are formed when an irritant, such as a bit of food, a grain of sand, bacteria, or even a piece of the mollusks mantle becomes trapped in the mollusk. To protect itself, the mollusk secretes the substances aragonite (a mineral) and conchiolin (a protein), which are the same substances it secretes to form its shell. The composite of these two substances is called nacre, or mother-of-pearl. The layers are deposited around the irritant and it grows over time, forming the pearl. Depending on how the aragonite is arranged, the pearl may have a high luster (nacre, or mother-of-pearl) or a more porcelain-like surface that doesnt have that luster. In the case of the low-luster pearls, the sheets of aragonite crystals are perpendicular to or at an angle to the surface of the pearl. For the iridescent nacreous pearls, the crystal layers are overlapping. Pearls may be a variety of colors, including white, pink, and black. You can tell an imitation pearl from a real pearl by rubbing them on your teeth. Real pearls feel gritty against the teeth due to the layers of nacre, while imitation ones are smooth. Pearls are not always round. Freshwater pearls are often shaped more like puffed rice. Unusual shapes can also be prized for jewelry, especially for large pearls. Which Mollusks Make Pearls? Any mollusk can form a pearl, although they are more common in some animals than in others. There are animals known as pearl oysters, which includes species in the genus Pinctada. The species Pinctada maxima (called the gold-lipped pearl oyster or silver-lipped pearl oyster) lives in the Indian Ocean and the Pacific from Japan to Australia and produce pearls known as South Sea Pearls. Pearls may also be found and cultured in freshwater mollusks and are often produced by species collectively called pearl mussels. Other pearl-producing animals include abalones, conchs, pen shells, and whelks. How are Cultured Pearls Made? Some pearls are cultured. These pearls do not form by chance in the wild. They are helped by humans, who insert a piece of shell, glass, or mantle into a mollusk and wait for pearls to form. This process involves many steps for the oyster farmer. The farmer must raise the oysters for about three years before they are mature enough to implant, keeping them healthy. Then they implant them with the graft and nucleus and harvest the pearls 18 months to three years later. As natural pearls are very rare and hundreds of oysters or clams would have to be opened to find one wild pearl, cultured pearls are more common.

Cell Phones While Driving Essay - 642 Words

Cell Phones and Driving In today’s society we’ve all become attached to our cell phones. Cell phones make our lives easier in many ways we can check our email, receive phone calls, send text messages, listen to music, and take pictures, all at our finger tips. With all this convenience, however there is a dangerous side to cell phones, and that’s when we use them while driving. Most of us are guilty of using cell phones while driving, but have we ever thought about its danger? Five states plus Washington D.C. have put hand held bans on cell phones while driving. California, Washington, New York, New Jersey, Connecticut, and Washington D.C. have hand-held bans, and many states have bans for specific drivers (Cummings). Maine has a ban†¦show more content†¦60 percent of teens admitted to risky driving. Nearly half of those drivers admitted to text messaging while driving (EdgarSnyder). In April, 2009, in Houston Texas five children lost their lives when the car they were in lost control and slid into a rain swollen ditch. The driver lost control of the vehicle when he went to answer his ringing cell phone. The car went into the ditch and was swept 100 feet down the raging current. The rescue team was unable to reach the car with the trapped passenger. Two adults and one ten year old girl were able to escape, but five children under the age of seven all passed away (.argusleader). A 17 year old girl was driving in Jacksonville Florida. She said that she â€Å"just Gilbert3 glanced down at her cell phone† when she struck a 44 year old man. He was working on side of the road with his tree trimming crew when he was struck by the distracted driver. The man was pinned between the car and the wood chipper. The man was listed in critical condition, but his injuries are not life threatening. A recent ban on texting while driving was passed in Florida. There may be charges brought against the young driver (www.foryourprotection.com). I believe that there should be a law put in effect nation wide to ban all cell phone use while driving. We all need to realize the danger and start by not answering, calling, or texting will weShow MoreRelatedCell Phones While Driving1322 Words   |  6 PagesShould cell phone use be banned while driving? Since the mid–1990’s, cell phones have been a part of our daily lives. Cell phones allow us to communicate with anyone, anytime, and anywhere even while we are driving, they are convent and make our lives easier. But is it safe to use a cell phone to talk, text, take pictures, surf the web, etc. while driving? Many drivers, especially young drivers think so. Many drivers do not think that glancing down at a cell phone for a few seconds to send orRead MoreCell Phone While Driving949 Words   |  4 PagesCell phone usage while driving is a major source of distraction that could potentially lead to accidents and consequently cause injury or loss of life. Technology has had a way of dealing with distractions by coming up with hands-free cell phones mounted on the dashboards of most vehicles. But, even so, cell phones are still a source of distraction when driving regardless of the fact that they are hand-held or not. Therefore, even the choice for authorities to come up with handheld bans still thatRead MoreUse Of Cell Phones While Driving860 Words   |  4 PagesAmericans rely heavily on cell phones to perform daily activities. Cell phone are used for phone calls, email, sending text messages, surfing the internet, and performing other tasks. It is unfortunate that many of these daily activities occur while a person is driving. As a result, an increase of accidents and fatalities have occurred because of the use of cellular phones while driving. Using a cell phone while driving is an epidemic that has taken our nation by storm. Most drivers believe theyRead MoreThe Dangers Of The Cell Phone While Driving2183 Words   |  9 Pagesmillions of Americans are driving on the roads. There are truck drivers; family’s going on vacations, and many other people that share the roads. Everyone just wants to get to their location safely, but sadly, this always doesn’t happen. Each year thousands of Americans are killed due to distracted driving, even more are injured. It’s a dangerous problem that is getting larger by the day. One type of distracted driving that is more prevalent is talking on the cell phone. Everyone is affected by thisRead MoreUse of Cell Phones While Driving824 Words   |  4 PagesIf you are driving at 55mph for 5 seconds in that amount of time you could cross a football field. People don’t understand how dangerous distracted driving really is. All states should have some sort of legal pa rameters of what happens when you get caught using your cell phone while driving. People should get a stronger/ harsher punishment for the use of a cellular device while driving. People are way more impaired when you are distracted and driving than you are drinking and driving. The problemRead MoreThe Use Of Cell Phones While Driving1817 Words   |  8 Pagesthat the use of cell phones while driving decreases driver awareness and overall road safety, and in response to this knowledge, some states have passed laws that have prohibited the use of handheld devices. However, there are no laws banning hands free cell phone usage, despite research claiming hands free devices are just as dangerous handheld devices. But, does their usage distract drivers enough to the point where states should legally ban the total use cell phones while driving? The followingRead MoreCell Phone Use While Driving1503 Words   |  7 Pagesforth over the lines or driving at very inconsistent speeds. You wonder what could possibly be causing the driver to drive so erratically. Is the driver drunk? Is the driver preoccupied with eating his or her lunch? Is the driver busy attending children in the backseat? Once you pull along the side you realize that was not the case, instead you no tice the driver has a cellular telephone up to her or his ear chatting away, or even worse you pass and see the driver holding a phone texting, you pass byRead MoreCell Phone Dangers While Driving1046 Words   |  5 PagesCell-Phone Dangers While Driving Introduction Today, we use our cell phones for just about anything and everything to include; texting, talking to our loved ones, and connecting with the rest of the world via social media. Cell phones have become a natural way of life to where we pick up our phones and use them like second nature. However, the dangers present themselves when we get behind the wheel of a car and carry these habits of cell phone addictions with us. If all states ban the use of cellRead MoreCell Phone Use While Driving990 Words   |  4 Pages Cell phones are integral to people’s lives in Canada because they are vital communication and entertainment tools. However, the use of cell phones has remained contentious, because texting and talking on the phone are associated with distracted driving. Distracted driving is, â€Å"defined as the diversion of attention away from activities critical for safe driving toward a competing activity† (Klauer, Guo, Simons-Morton, Ouimet, Lee Dingus, 2013, p. 55). Alth ough distracted driving is also associatedRead MoreCell Phone Use While Driving1114 Words   |  5 PagesToday, we use our cell phones for just about anything and everything to include; texting, talking to our loved ones, and connecting with the rest of the world via social media. Cell phones have become a natural way of life to where we pick up our phones and use them like second nature. However, the dangers present themselves when we get behind the wheel of a car and carry these habits of cell phone addictions with us. If all states ban the use of cell phones while driving, then there would be a reduced

Creationism In Schools Essay Example For Students

Creationism In Schools Essay Teaching Creationism in SchoolsThe question as to whether or not creationism should be taught in public schools is a very emotional and complex question. It can be looked at from several different angles, its validity being one of them. Despite the lack of evidence to support the fundamentalist idea of creationism, that in itself is not enough to warrant its exclusion from the curriculum of public schools in the United States. The question is far more involved and complex. One way to address the question is whether or not creationism, in itself, is a valid idea to be taught in public schools. The answer to this can be yes. Not only should a student in American public schools learn and acquire knowledge in empirical sciences, and other tangible facts both in history and other courses, but he should also learn how to think and make decisions for himself. Unfortunately, as it turns out, creationism is in direct conflict with the biological theory of evolution. Many fundamentalist propose that creationism should replace, or at least be offered as an alternative to Darwins theory of evolution.This is not the right approach. Creationism, as exemplified in the book of Genesis, should not be taught in a science course. Science runs on a certain set of rules and principles being: (1) it is guided by natural law, (2) it has to be explanatory by reference to natural law, (3) its conclusions lack finality and therefore may be altered or changed, (4) it is also testable against the empirical world, and finally (5) it is falsefiable. These characteristics define the laws, boundaries, and guidelines that science follows. In a science course, all knowledge conveyed is shown, or has been shown in the past, to exemplify a strict adherence to these qualities. Creationism, unfortunately in the eyes of Christian fundamentalist, does not exemplify any adherence whatsoever to these rules and guidelines of science. Therefore, it should not be included in the science curriculum in public schools, even as an alternative to evolution. Another idea is that which is held by those who subscribe to the idea of scientific creationism. Scientific creationism, as it relates to this topic, states that God was the creator, and that evolution is simply a means, developed by Him, of conservation. Due to this definition of how scientific creationism relates to evolution, it may be easier to accept by scientific criteria, despite the fact that the origins are scientifically debatable. The problem in scientific creationism, and what I see as a reason for its exclusion from the science classroom in public schools, is the fact that it looks as if, from the outside, the whole theory that it rest on is simply a contortion of the traditional version of creation described in Genesis, custom-made to fit in with Darwins theory of evolution. R. M. Hare would probably say that scientific creationism is simply a modification of the story of creation in Genesis, to fit into the blik of the religious fundamentalist. A blik, as Hare describes it, is a pre-set world view held by all people, in which they draw from when forming certain opinions on any particular subject. In the case of religious fundamentalist, whos faith in the validity of the Book of Genesis is an essential part of their blik, it becomes necessary for them to contort their literal view of the Book of Genesis into a form that is scientifically acceptable. For this reason, creation science still does not have a place in the science classroom of public schools. Another problem with scientific creationism is that it would exclude the idea of a random beginning. .u9880f3cc18456dcaf8cda904e6eda62c , .u9880f3cc18456dcaf8cda904e6eda62c .postImageUrl , .u9880f3cc18456dcaf8cda904e6eda62c .centered-text-area { min-height: 80px; position: relative; } .u9880f3cc18456dcaf8cda904e6eda62c , .u9880f3cc18456dcaf8cda904e6eda62c:hover , .u9880f3cc18456dcaf8cda904e6eda62c:visited , .u9880f3cc18456dcaf8cda904e6eda62c:active { border:0!important; } .u9880f3cc18456dcaf8cda904e6eda62c .clearfix:after { content: ""; display: table; clear: both; } .u9880f3cc18456dcaf8cda904e6eda62c { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .u9880f3cc18456dcaf8cda904e6eda62c:active , .u9880f3cc18456dcaf8cda904e6eda62c:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .u9880f3cc18456dcaf8cda904e6eda62c .centered-text-area { width: 100%; position: relative ; } .u9880f3cc18456dcaf8cda904e6eda62c .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .u9880f3cc18456dcaf8cda904e6eda62c .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .u9880f3cc18456dcaf8cda904e6eda62c .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .u9880f3cc18456dcaf8cda904e6eda62c:hover .ctaButton { background-color: #34495E!important; } .u9880f3cc18456dcaf8cda904e6eda62c .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .u9880f3cc18456dcaf8cda904e6eda62c .u9880f3cc18456dcaf8cda904e6eda62c-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .u9880f3cc18456dcaf8cda904e6eda62c:after { content: ""; display: block; clear: both; } READ: lord of files Essay No theory could ever be tested to find origins because it would conflict with scientific creationism. Scientific creationism would be, in essence, a lesson on science halting efforts to find creation, if it is possible at all. It may, however, be acceptable as a theory and not a solid law. Now that it is clear that creationism, as well as scientific creationism, does not fit into the guidelines on which science operates, therefore making them unsuitable for teaching in science classrooms in public schools, in what part of the public school curriculum in