Biology

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The Lymphatic System The lymphatic system is a collection of ducts organs and tissues, which collect excess fluid or lymph from your body and transport it back to the heart. The lymphatic system also helps to defend the body against infection. Lymph vessels of the neck These lymph vessels drain tissue fluid, or lymph, from the head and neck. The fluid is filtered through lymph nodes in order to remove foreign particles before it re-enters the bloodstream. This helps to defend your b

BACTERIA ( Gr. bakterion, "little staff"), group of microscopic, unicellular organisms that lack a distinct nucleus and that usually reproduce by cell division. are tiny, ranging from 1 to 10 micrometers (1 micrometer equals 1/25,000 in), and are extremely variable in the ways they obtain energy and nourishment. They can be found in nearly all environments-from air, soil, water, and ice to hot springs; even the hydrothermal vents on the deep ocean floor are the home of sulfur-metabolizing bacter

quantities of material with which to work. The process of engineering a DNA fragment into a vector is called "cloning," because multiple copies of an identical molecule are produced. Another way, recently discovered, of produsufficient cing many identical copies of a particular DNA fragment is polymerase chain reaction. This method is rapid and avoids the need for cloning DNA into a vector. Therapy. form of genetic engineering involves supplying a functional gene to cells lacking that function,

Archaebacteria, simple organisms that resemble ordinary bacteria in that they lack a well-formed nucleus and can therefore be characterized as procaryotes in the classification of living organisms. Their biochemistry differs in important ways from that of other bacteria, however, and some biologists place them in a kingdom of their own. According to these theories, archaebacteria may be ancestral to the main cellular body of eucaryotes, or organisms with well-formed cell nuclei, whereas ordinary

Bacteria comes from the Greek word meaning "Little Staff" (Infopedia) (or more appropriately "Staph") which most likely refers to some form of Bacillus, but what is bachteria and why do we need it. When most people think of the idea of little crawlies on their skin, they pretty much freak (See Jackie Plank), but we need to see is the difference between the pathogens and the helpful bacteria, the good and the bad, the yin and yang of monerans. Koch (1843-1910) is often considered the founder

The second law of thermodynamics states that energy transitions are imperfect. No matter what, energy is lost. In machines an 75% loss of energy is considered average. In biological reactions there is usually a 60% loss. Since all reactions are constantly losing a percentage of the energy they give, it is necessary to have a constant intake of energy to make up for what is lost. This intake of energy helps life to remain ordered. If something disrupts that order, entropy begins to take eff

Big Brown Bat Eptesicus fucus Kingdom: Animalia Phylum: Chordata (organisms that possess a structure called a notochord) Class: Mammalia (3 middle ear bones; hair; and the production of milk by modified sweat glands called mammary glands.) Order: Chiroptera (winged) Family: Vespertilionidae (This is the largest family of bats: it includes 35 genera and 318 species! With this many species there are exceptions to almost every generalization about this

Frogs Frogs are amphibians in the order Anura. The order Anura is broken down into twenty-two different families of frogs and toads. Although they belong to the same order, frogs and toads are different in a lot of ways. Some of the more distinct differences are their skin and where they live. Frogs usually have smooth, moist skin, and toads usually have dry, warty-looking skin. Frogs spend most of their lives in or near water, and toads spend more time on land. Amphibian means "d

A debate is currently raging throughout the world, from the halls of the United States Congress and the President's Oval Office to the United Nations and the World Health Organization. The issue: the cloning of human beings. Ever since researchers in Scotland cloned an adult sheep named Dolly over a year ago, the issue of applying this technology to reproducing human duplicates has been paramount in scientific and social circles. The debate is not merely confined to scientists; everyone fr

Close Encounters With the Effects of Time Dilation How does it feel to be going speeds near that of the speed of light? What is it like to return to Earth to find that your best friend who was the same age as you is now older than you? You might talk to a man named Bob Smith. Bob recently returned from his trip to the edge of the universe and we were fortunate enough to talk to Bob about what he experienced on his journey. We also got the opportunity to talk with Bob's close friend, J