.... from the body which increase surface area over which gas exchange can occur. Inside the gills of aquatic animals, the circulatory system removes oxygen, and delivers waste carbon dioxide. Land vertebrates have developed a different approach to the problem of gas exchange, as water is not present in all of the terrestrial environment. Terrestrial vertebrates have developed lungs to solve this problem. Air enters through the nasal passages, or the mouth, passes through the trachea, then branches off at the two bronchi, and goes through many branching passages called bronchioles, which end in alveoli. Alveoli are sack-like structures where the circulatory system meets the res ....

.... triggers the activation of adrenylyl cyclase. This communication would not be possible if not for the guanine nucleatides that allow the binding of the enzymes to occur. Not only does epinephrine trigger the chemical reactions by bonding to the guanine nucleotides, but they also trigger the production GDP by reducing GTP to its subserviant level. Not all effectors are triggered by simply hormones. Cells in the retinal area of the eye are triggered by photons that strike rhodopsin. When the rhodospin it activates the G protein, transductin, to travel to the effector enzyme, and thus regulates the levels of soduim ions (Na+). The eye cells become hyperpolarized, thus pr ....

.... breath of air. The symptoms of this deadly virus starts with sudden fevers, weakness, muscle pain, extreme headaches, and soar throats. These symptoms begin four-sixteen days after infection. After about 2 days of these symptoms you start to "crash". A crash is when you vomit uncontrollably until there is nothing left to vomit (you vomit blood, bile and other liquids of the body), you suffer from diarrhea, limited kidney function, internal and external bleeding, you bleed from every opening on your body, blood fails to clot, so if you get cut in any way your body will never stop bleeding from that wound. Ebola could spread and infect everyone in the world in 48 hours. Marb ....

.... response to this news, here and abroad, was primarily one of concern. In some cases, these concerns were amplified by largely fictional and mistaken accounts of how this new technology might dramatically reshape the future of our society. The sources of these feelings were complex, but usually centered around the basic fact that this technique would permit human procreation in an asexual manner, would allow for an unlimited number of genetically identical offspring, and would control over the genetic profile of our children (Hopkins, 8). Eugenics is accomplished through a field of science known as eugenics, which basically is an attempt to improve the human race. Adva ....

.... same, thus ensuring that the widow bird nestlings can grow up among their alien nestmates with no risk of being rejected by their foster parents. MASTERS OF DISGUISE Things aren't always as they seem, and nowhere is this more true than in nature, where dozens of animals (and plants) spend their time masquerading as others. So clever are their disguises that you've probably never known you were being fooled by spiders impersonating ants, 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 ....

.... do or act like. They had to get all of their knowledge of what to do from outside sources, such as television and movies. The guards were given uniforms and night sticks and told to act like an ordinary guard would. The prisoners were treated like normal criminals. They were finger printed and booked, after that they were told to put on prison uniforms and then they were thrown into the slammer (in this case a simulated cellblock in the basement was used). All of the participants in this experiment at first were thought to be similar in behavior but after one week, all of that changed. The prisoners became "passive, dependent, and helpless." The guards on the other ha ....

.... New York. Little Echo Pond has a pH of 4.2. Lakes and streams in the western United States are usually not acidic. Because of differences in emissions and wind patterns, levels of acid deposition are generally lower in the western United States than in the eastern United States. This chart shows that not all fish, shellfish, or their food insects can tolerate the same amount of acid: Generally, the young of most species are more sensitive than adults. Frogs may tolerate relatively high levels of acidity, but if they eat insects like the mayfly, they may be affected because part of their food supply may disappear. As lakes and streams become more acidic, the numbers and ....

.... of electric current in treatment without the generation of intense heat. This includes electric stimulation of nerves or muscles, passage of current into the body, or use of interrupted current of low intensity to raise the threshold of the skin to pain. Studies suggested this therapy is applied to conditions such as ulcers, traumatic or burn wounds, osteoarthritis, and cancer. Electrical stimulation is simply the application of electrical pulses to the body, whether it is for function or therapy. The classical and common example is that of the cardiac pacemaker. The range of clinical uses of electrical stimulation has and is growing wider and includes: pain relief (often ....