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Search results 4211 - 4220 of 14240 matching essays
- 4211: Plant Breeding
- ... not have to rely on accidents. They can attempt to produce fertile polypodies by crossbreeding between different species. One early attempt to produce another hybrid species was made in 1927 by the Russian geneticist G. D. Karpechenko, who crossbred two quite distantly related species, a radish and a cabbage. Each species has eighteen chromosomes (nine pairs); the hybrids had the same number (nine radish chromosomes and nine cabbage chromosomes) and were ... cold winters to the usual properties of wheat. Recent breeding programs have led to highly inbred wheats. Much of the genetic variability, that accumulated over nine thousand years of wheat cultivation, is missing from present day varieties. If a new disease should arise, or if the climate were to change suddenly, much of the wheat might be damaged and lost. So it is a good idea to introduce other genes into ...
- 4212: Revolutionary QM212
- ... the objects. This slot can be customized, through manipulation and modelling, to fit many different objects. Therefore, objects such as viruses, poisonings, or bacteria, could be jetted out of ones body. This aspect could one day benefit millions of people around the world. Chemical Process: Teams from universities successfully inserted instructions for building an anti-fluorescein antibody in the DNA of bacteria. This antibody binds with fluorescein molecules. Into this chunk ... would be used to replicate synthetic antibodies instead. Creating molecules with the uncanningly precise seek-andΔ destroy capabilities of natural antibodies is an exciting step in replicating nature's fascinating immune system. Bibliography Uehling, Mark D. "Birth of a Molecule." February 1992, p. 74
- 4213: Alchemy
- ... The first practical alchemist may be said to have been the Arbian Geber, who flourished 720-750. From his "Summa Perfectionis", we may be justified in assuming that alchemical science was already matured in his day, and that he drew his inspirations from a still older unbroken line of adepts. He was followed by Avicenna, Mesna and Rhasis, and in France by Alain of Lisle, Arnold de Villanova and Jean de ... in the forties of the last century he frequented the laboratory of a certain Monsieur L., which was the rendezvous of the alchemists in Paris. When Monsieur L`s pupils left the laboratory for the day, the modern adepts dropped in one by one, and Figuier relates how deeply impressed he was by the appearance and costumes of these strange men. In the daytime, he frequently encountered them in the public ... he could nothing in common with those of his strange companions. He confounded the wisdom of the alchemical adept with the tenets of the modern scientist in the most singular fashion, and meeting him one day at the gate of the Observatory, M. Figuier renewed the subject of their last discussion, deploring that " a man of his gifts could pursue the semblance of a chimera." Without replying, the young adept ...
- 4214: Evolution
- ... disagreement, even to the point of publishing a work of his own entitled Darwinism. This itself was his single greatest contribution to the field: encouraging Darwin to publish his extensive research on the issues they'd both developed22. He later published Contributions to the Theory of Natural Selection, comprising the fundamental explanation and understanding of the theory of evolution through natural selection. He also greatly developed the notion of natural barriers ... House Encyclopedia, The. New York: Random House Inc., 1987, p. 406-25. 14 Ridley, Mark. The Essential Darwin. London, Eng: Allen & Unwin, 1987. 15 Smith, J.M. On Evolution. London: Doubleday, 1972. 16 Stansfield, William D.. Genetics 2/ed. New York: McGraw-Hill Book Company, 1983, p.266-287. 17 Thomas, K.S.. H.M.S. Beagle, 1820-1870. Washington: Oxford University Press, 1975. ENDNOTES _______________________________ 1. Johnathan Miller, Darwin for Beginners ... Anchor Press/Doubleday, p. 177. 39. ibid., p. 156. 40. opsit., p. 218. 41. opsit., p. 408. 42. opcit., p.431. 43. ibid., p. 432/ 44. opsit., p. 253. 45. ibid., p. 554. 46. William D. Stansfield, Genetics 2/ed, New York: McGraw-Hill Book Company, 1983, p. 266. 47. ibid. p. 269. 48. opsit., p. 272. 49. ibid., p. 274. 50. ibid., p. 275. 51. opsit., p. 434. 52. ...
- 4215: DNA: The Thread of Life
- ... as DNA. It is the spiral shaped molecule found in the nucleus of cells. Scientists have known since 1952 that DNA is the basic substance of heredity. This was hypothesized, and later confirmed by James D. Watson and Francis Crick. They also know that it acts like a biological computer program over 3 billion bits long that "spells" out instructions for making the basic building blocks of life. DNA carries the ... to make a detailed map of every single gene in human DNA. With automated cloning equipment to steer scientists through the DNA, scientists are finding human genes at the rate of more than one a day. This may not sound like very much but as technology increases the rate at finding them will increase. Since January 1993 to January 1994 scientists have located the genes for Huntington's disease, Lou Gehrig ...
- 4216: Introduction To Evolution
- ... began as to the existence of a sort of blood relationship between these species. These questions coupled with the emerging sciences of geology and paleontology gave rise to hypotheses that the life-forms of the day evolved from earlier forms through a process of change. Extremely important was the realization that different layers of rock represented different time periods and that each layer had a distinctive set of fossils of life ... appendages of the sea turtle (reptile), penguin (bird), and walrus (mammal). MOLECULAR EVOLUTION An outpouring of new evidence supporting evolution has come in the 20th century from molecular biology, an unknown field in Darwin's day. The fundamental tenet of molecular biology is that genes are coded sequences of the DNA molecule in the chromosome and that a gene codes for a precise sequence of amino acids in a protein. Mutations ... proteins. Over evolutionary time, proteins have had histories that are as traceable as those of large-scale structures such as bones and teeth. The further in the past that some ancestral stock diverged into present-day species, the more evident are the changes in the amino-acid sequences of the proteins of the contemporary species. PLANT EVOLUTION Biologists believe that plants arose from the multicellular green algae (phylum Chlorophyta) that ...
- 4217: The Canada Goose
- ... distance call to goslings, special greeting for female, adult distress, gosling distress, and gosling contentment call as well as a scream of pain when the bird is bitten (Wormer). It takes a female goose a day to a day and half to lay an egg (Wormer). Each goose lays and average of five to six eggs, sometimes only two and sometimes one goose may lay eleven to twelve eggs (Wormer). With sixty percent of ... even migrate across the ocean to Japan (Ross) (Refer to maps 1 and 2 for wintering areas and densities of geese). Canada Geese like to feed mid-morning and just before sunset leaving the mid-day for relaxing. Canada Geese graze cord grass, spike rush, naiad, glasswort, bullrush, salt grass, seepweed, Bermuda grass, golden dock, lycium, brome grass, wild barley, rabbit-foot grass, pepper grass, saltbush, cattail, alkali grass, and ...
- 4218: Investigation of Reproduction and Development in Animals
- ... misuse it, the actual failure rate is more like three percent. The pill does not provide protection against sexually transmitted diseases. How are pills used? One pill must be swallowed at the same time every day. It is not any single pill, but the day-to-day process of taking the pill which provides protection against pregnancy. What is infertility? Infertility in humans and other species(animals) is the inability to concieve or carry a pregnancy to a live birth. The ...
- 4219: Biome Broadcast
- ... to seventy five degrees and there was barely any humidity. Even though we have all four seasons and varied amounts of precipitation throughout the year it felt like it was either a scorching humid summer day or it was a freezing snowy winter day. It felt like we only had two seasons all year either summer or winter. When we stepped out of the car we could see and hear birds singing. We could also smell, hear, and see ... to take. We had three choices the first trail was half a mile long, the second trail was two miles long, and the third trail was four miles long. Since it was such a beautiful day we all decided to take the third trail that was four miles long. We started hiking around 11:00 AM. While we were hiking we heard wings flapping, we all turned and saw a ...
- 4220: Bats
- ... in the form of clicks that increase as the bat gets closer to the insect or whatever it is tracking (Bats in CT). Unlike humans most insects can hear the bat's echolocation sounds. David D. Yager of the University of Maryland has found that the praying mantis has used this to its advantage. When being pursued by a bat the mantis can hear the clicks of the bat behind it ... and bats will go on forever because they will counter each others counter measures of how an animal can evolve to how amazing abilities. Bats have evolved to fly, use echolocation, hibernate, sleep in the day, hang by their feet, and many other things that individual species have developed. Some large bats, called megabats, are even thought by some scientists to be closely related to primates because of their similar brain ...
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