.... or more tissues that function together make up organs. An organ system is a group of organs that work together to carry out major life functions. Eukariotic Cell Structure: Boundaries and Control: Plasma Membrane - The plasma membrane is sometimes called the cell membrane, or the cellular membrane. It is the outermost part of the animal cell, and it's purpose is to enclose the cell, and change shape if needed. The cell membrane is capable of allowing materials to enter and exit the cell. Oxygen and nutrients enter, and waste products such as excess water leave. The plasma membrane helps maintain a chemical balance within .....

.... Fulita, an atmospheric scientist from the University of Chicago, coined the term downburst for a concentrated, sever downdraft that induces an outward burst of damaging winds at the ground. He also introduced the term microburst for a downburst with horizontal dimensions of 4km or less (Lester 11-4). Microbursts form by the same process that produce the more common and less intense down drafts; that is, by precipitation drag and cooling due to the evaporation and melting of precipitation particles. In a microburst, the downdraft intensifies with heavy rain and when dry air is mixed into the downdraft causing evaporative cooling an .....

.... had been converted to a race track, complete with race cars, fences, and spectators. The 767 crash landed, and, fortunately, no one was killed. Their were many contributing factors that made this plane run out of fuel. First of all, the computerized fuel gauge was not working, and a maintenance worker said , incorrectly, that the plane was still certified to fly. To measure the amount of fuel remaining, they use a drip stick method. They discovered that their was 7 682 liters in the tank. However, they had always measured fuel in the past as pound, while the 767 consumed fuel in kilograms. The drip sticks did not ex .....

.... squirrels that look like shrews, worms copying sea anemones, and roaches imitating ladybugs. There are even animals that look like themselves, which can also be a form of impersonation. The phenomenon of mimicry, as it's called by biologists, was first noted in the mid-1800s by an English naturalist, Henry W. Bates. Watching butterflies in the forests of Brazil, Bates discovered that many members of the Peridae butterfly family did not look anything like their closest relatives. Instead they bore a striking resemblance to members of the Heliconiidae butterfly family. Upon closer inspection, Bates found that there was a .....

.... global extinction rate is estimated at about 20,000 species per year, exponentially greater than the background extinction rate (17). Many biologists believe that we are in the middle of the greatest mass extinction episode since the disappearance of the dinosaurs 65 million years ago (18). The survival of ecosystems (plant and animal communities and their physical surroundings) such as forests, coral reefs, or wetlands depend on their biodiversity or variety of plants, animals, and habitats, as well as the many interactions among these species. The removal or disappearance of one or several species may irreversibly damage th .....

.... needed to keep the baby alive and the baby has to be transported to a bigger hospital, usually to a hospital in a metropolitan city in order to get the proper care. After the baby has been assessed for problems then it is watched closely for the next 48 hours. This is the most critical time for a baby . During this time the doctors can determine if the baby is going to have a long road ahead of them or if the baby is healthy and will pull through the whole thing with flying colors. Sometimes, they may seem healthy and are progressing well and then they could have a turn for the worse without any warning signs at all. For a parent .....

.... coping behavior. More recently, and probably more accurately, it has come to be viewed as a complex disease entity in its own right. Alcoholism usually develops over a period of years. Early and subtle symptoms include placing excessive importance on the availability of alcohol. Ensuring this availability strongly influences the person’s choice of associates or activities. Alcohol comes to be used more as a mood-changing drug than as a foodstuff or beverage served as a part of social custom or religious ritual. Initially, the alcoholic may demonstrate a high tolerance to alcohol, consuming more and showing less adverse effects th .....

.... the presynaptic cell to the posisynaptic cell. Structural Classification *Anaxonic neurons- have multiple processes and the axon is indistinguishable from the from the dendrites. They're fairly small. *Bipolar neurons- have two processes in which one is a dendrite, and the other an axon. The dendrite is distinguishable from it's extensive branching at it's distal end. it's less than 3Omm from tip to tip. *Unipolar neurons- have a continuous dendritic and axonal process, in which case the cell body lies off to the side. The dendritic end of the process has extensive branching, the anoxic part of the proces .....

.... coating that causes normal healthy cells to stay together because cancerous cells lack it they can break off and implant somewhere else in the body. The cancerous cells that break off from the primary tumour are usually carried through the blood. What causes cancer cells to be abnormal? They create extra chromosomes and more DNA then normal cells do. Lung Cancer What usually happens with lung cancer is that the cilia in your throat that usually help keep chemicals and other harmful particles out are destroyed sometimes by smoking or if you work around certain chemicals. What happens is that harmful chemicals get into your .....

.... to such an extent that it does not filter out the sun's invisible and dangerous ultraviolet rays " ( Jones, 1992, p.36 ). Such a scenario would drastically alter society and the environment. Ozone depletion has been described as "potential catastrophe " and " a planetary time - bomb " ( Way, 1988, p.9 ). The four main areas affected by a depleted ozone layer and thus by the corresponding increase in harmful ultraviolet radiation are agriculture, wildlife, the environment, and human health. A depleted ozone layer has a profoundly negative and potentially devastating effect on humanity and its surroundings. From an agricultural .....