... molecules in the upper atmosphere." Lightening and sparks from motors also convert oxygen to ozone ( Stoker 1). The question about the destruction of the ozone layer revolves around whether human-made CFCs (chloroflurocarbons) used in air- conditioners and refrigerators are breaking it down. This is the ozone thinning theory: "CFCs release chlorine into the stratosphere... leading to ozone destruction and exposing the planet to harmful ultraviolet rays." Critics who discount the thinning theory still say that chlorine comes from natural sources like volcanic eruptions and does no permanent damage (Brooks 422). NASA researches claim that they have evidence that s ...
Words: 1143 - Pages: 5
... and started their cloning saga also. In one method of artificial cloning used in plant breeding, cells are cut from a plant and placed in a flask with a nutrient medium. The cells grow and divide, forming embryonic tissues that are transferred to soil, where they produce complete plants. Grafting is another method of cloning used in Horticulture. Matching cuts are made in the stems of two plants, which are then fitted together so that their transport systems are in contact. The wounded area heals, and the two stems become a single physiological unit. All the McIntosh apple trees now in use and many other fruit varieties have been derived by grafting from single anc ...
Words: 1212 - Pages: 5
... by integrating evolutionary and transmissibility factors. INTRODUCTION Why do certain parasites exhibit high levels of virulence within their host populations while others exhibit low virulence? The two prime factors most frequently cited (Esch and Fernandez 1993, Toft et al. 1991) are evolutionary history and mode of transmission. Incongruently evolved parasite-host associations are characterized by high virulence, while congruent evolution may result in reduced virulence (Toft et al. 1991). Parasites transmitted vertically (from parent to offspring) tend to be less virulent than parasites transmitted horizontally (between unrelated in ...
Words: 2924 - Pages: 11
... needs to be banned because of the social, religious, ethical, and legal implications. The first step to understanding genetic engineering is to know the start of its creation. Genetics achieved its first foothold on the secrets of nature's evolutionary process, when an Austrian Monk named Gregor Mendel developed the basics of how genetics work. Using this, scientist studied the characteristics of organisms for the next one hundred years following Mendel's discoveries. These early studies concluded that each organism has two sets of character determinants, genes (Stableford 16). For instance, in regards to eye color, a child could receive one set of genes fr ...
Words: 1929 - Pages: 8
... They then turned this destructive power into huge plants generating"clean and cheap"electricity for the country. It was called progress. Progress also brought with it sickness, mutations, cancer and eventually death to those exposed to high levels of radiation. Government declared that nuclear power is safe and efficient. Also have big Oil corporations who have a lot of money invested in nuclear power and want to see as many plants as possible put into and kept in operation. The truth is that accidents do happen at nuclear power plants and at other facilities all the time. An accident at a nuclear power plant has the potential to be much more devastating tha ...
Words: 2297 - Pages: 9
... that they form a grove or pocket on the surface. The substrate fits in to this grove, which is the site of reactions catalyzed by the enzyme, or active site. Recent studies of enzyme structure have suggested that the active site is flexible. The binding between and substrate appears to alter the shape of the enzyme. This induces a close fit between the active site and the substrate. It is also believed that this may put some strain on the substrate molecule facilitating the reaction. Another characteristics of are competitive inhibition and non-competitive inhibition. Competitive inhibition is the binding of a competitive molecule to the active site of the e ...
Words: 368 - Pages: 2
... periodic table. Though widely distributed at the Earth's surface, gallium does not occor free or concentrated in independant minerals, except for gallite. It is extracted as a by-product from zinc blende, iron pyrites, bauxite, and germanite. Silvery white and soft enough to be cut with a knife, gallium takes on a bluish tinge because of superficial oxidation. Unusual for its low melting point ( about 30 degrees C, 86 degrees F ), gallium also expands upon solidification and supercools readily, remaining a liquid at temperatures as low as 0 degrees C ( 32 degrees F ). Gallium has the longest usefull liquid range of any element. The liquid metal clings to ...
Words: 487 - Pages: 2
... medium in which there are roughly equal numbers of positively and negatively charged particles, produced when the atoms in a gas become ionized. It is sometimes referred to as the fourth state of matter, distinct from the solid, liquid, and gaseous states. When energy is continuously applied to a solid, it first melts, then it vaporizes, and finally electrons are removed from some of the neutral gas atoms and molecules to yield a mixture of positively charged ions and negatively charged electrons, while overall neutral charge density is maintained. When a significant portion of the gas has been ionized, its properties will be altered so substantially that li ...
Words: 2677 - Pages: 10
... be more severe in some areas than in others. Catastrophic generally occur at latitudes of about 15°-20° and in areas bordering the permanently arid regions of the world. Lands that are permanent arid is a characteristic of those areas where warm, tropical air masses, in descending to earth, become hotter and drier. When a poleward shift in the west ocurrs, the high-pressure, anticyclonic conditions of the permanently arid regions hit each other on areas that are normally used to seasonally wet low-pressure weather and a drought follows. A southward shift in the western winds causes the most severe drought of the 20th century, the one that struck the African region ...
Words: 478 - Pages: 2
... problems. Aromatherapy also acts on the central nervous system, relieving depression and anxiety, reducing stress, relaxing, uplifting, sedating or stimulating, restoring both physical and emotional well-being. Although Aromatherapy is consider to be a new and alternative foram of medicine in the western world, however it has been practiced for thousands of years in the eastern world. A lot of interest in Aromatherapy stems from its use as an 'alternative medicine' or even a 'complementary medicine'. It is certainly true that before pharmaceutical companies brought a vast array of modern drugs to the market, people had to make do with many 'home remedies' - ofte ...
Words: 899 - Pages: 4
