.... charged ion. As an example of an ionic bond let's used the elements Cl and Na. First, we must understand that there is an attraction between them because one is positive and the other negative and that the Cl atom contains seven valence electrons and Na one. So, as the atoms bond the Na loses its valence electron and Cl gains it making its outer shell complete and it more stable. During this reaction light and heat are given off. This shows an exothermic reaction, which is a release of energy. The electrostatic energy between the two holds them together. Ionic bonds are useful because in a liquid state it can conduct electricity. This is possible because it contains ions. Th ....

.... and water into sugar or starch. This process was called photosynthesis. The next stage in the development in plants was 'The Age of Primitive Vascular Plants. This new period (the second stage) in plant history occurred within the next 50 million years (400-500 million years ago). Some of these developed root systems stems and leaves. They also formed woody tissue, which created stiffer stems, which eventually developed into tree trunks. They became tree-like and up to 40 meters tall, forming the world's first forest. 'The Age of Seed Bearing Plants' was the next stage of plant history where plants were taken to their next step up in the evolution. This occurred around 28 ....

.... with each passing year and experts are optimistic for the future; however, the threat of exists today and is a major cause for concern. The discovery of penicillin the 1940s proved to be the dawn of the antibiotic era. In less than two decades, major advancements had been made in the development of antibiotics. There were so many different antibiotics developed that doctors and scientists focused their attention on other problems plaguing the nation. Doctors prescribed antibiotics frequently, often when they were not even needed. According to a 1998 report by the Institute of Medicine, up to fifty percent of antibiotics are prescribed unnecessarily. This blatan ....

.... life span of a patient was five years .Today improved medical therapies and nurtrient rich diets have enabled suffers to survive into adulthood. Research into the cause of reads like a detective story. One clue is that patients have excess amounts of sodium and chloride in their sweat making it vey salty . At the University of North Carolina researchers found that salt imbalance caues thick mucus to accumulate in the patients lungd. High level of salt in lung cells draw water out of the mucus causing it to thicken.The level of salt in a cell is determained by the movement of ions across the cell membrane.Ions are carried across call memebranes by protein channels emb ....

.... 1996 Mycoplasma pneumoniae finished 1996 Saccharomyces cerevisiae finished 1997 Helicobacter pylori finished 1997 Escherichia coli finished 1997 Bacillus subtilis finished 1997 Archaeoglobus fulgidus finished 1997 The benefits of complete genome sequencing projects include a greater understanding of the organisms being sequenced and acknowledgment of the minimum complement of genes necessary for a free-living organism. Of the organisms that have already had their genomes sequenced, a number are of particular importance. For example, Mycoplasma genitalium has a complete nucleotide sequence that is only 580,070 base pairs long, and as such, is believed to be ....

.... oxygen produced from living things moves from the troposphere, the layer of air nearest to the earth surface, to the stratosphere. Air in the stratosphere absorbs solar energy, or heat from the sun, which in turn creates a photochemical reaction that produces ozone – a benefit to the environment since ozone protects people, plants, and animals from harmful radiation. The ozone layer is important because it absorbs most of the damaging ultra-violet radiation from the sun before it reaches ground level, where it can cause sun burn, skin cancer and cataracts. Research suggests that any additional UV-B (ultra-violet radiation) at ground level could depress our bodies’ immun ....

.... oceans will rise a possible 1 to 4 feet. Temperatures are expected to rise causing more rain in some places and less in others. Another provider to the greenhouse effect is the use of CFCs. CFCs, or chlorofluorocarbon, are used in making plastics and in aerosol spray cans, refrigerants, air conditioners, and similar objects. Like carbon dioxide, the CFCs are trapping more heat in the earth's atmosphere. CFCs have also been blamed for ozone depletion. CFCs are suspected of breaking down ozone particles that shield us from the sun's ultraviolet rays. Too many ultraviolet rays can cause cataracts and skin cancer. A hole in the ozone has been discovered over Antarctic the ....

.... doesn’t. The cell wall protects and gives structure to the cell. Then there is the Nucleus, which serves as a control center for the cell. Inside the Nucleus there are one or more Nucleoli. They are dense, granular bodies that disappear at the beginning of cell division and reappear at the end. Then you have the Cytoplasm. This is the watery material lying within the cell between the cell membrane and the nucleus. The Cytoplasm also contains organelles, which have specific functions in the cell metabolism. Then there are the Golgi Bodies, which serve as processing, packaging, and storage for the cell. These organelles package and ship things out. Another parts of th ....