Mendel's contribution to genetics?
353645
The laws of inheritance were derived by Gregor Mendel, a 19th century Austrian monk, who was conducting plant hybridity experiments. Between 1856 and 1863, he cultivated and tested some 28,000 pea plants. His experiments brought forth two generalizations which later became known as Mendel's Laws of Heredity or Mendelian inheritance. These are described in his paper "Experiments on Plant Hybridization" that was read to the Natural History Society of Brno on February 8 and March 8, 1865, and was published in 1866.
1164536
By Mendelian theory, no. (bb= blue, BB & Bb=brown)\nBlue eyes are a recessive trait \nbb x bb = only bb\nNow if they were Brown eyed with the blue recessive trait and a blue eyed spouse\nBb x bb = Bb Bb bb bb\n\n-----------BUT---------------------\n\nMost of us learned the model for determining eye color that G.C. Davenport and C.B. Davenport devised in 1907. The Davenport model wrongly says brown eye color is always dominant over blue eye color, which means that two blue-eyed parents always have blue-eyed kids. We know better now.\n\n"Although not common, two blue-eyed parents can produce children with brown eyes," says Richard A. Sturm, a Principal Research Fellow at the Institute for Molecular Bioscience at the University of Queensland in Brisbane, Australia.\n\nEye color is a complex trait that depends on the state of several interacting genes. The gene that usually decides the issue (blue eyes or brown eyes) is the OCA2 gene on chromosome 15. But it comes in different strengths. A person with a weak form of the OCA2 gene will have blue eyes. Likewise a person with a strong form will have brown eyes. \n\nThe plot thickens, though, because an individual also has other eye-color genes that each has a say in the final eye-color outcome. For example, if one of these lesser genes is strong, it can make the weak form (blue) of OCA2 work much more effectively — almost like the strong form (brown). Then the eye color may be a light brown or muddy grey. In fact, the resulting color can be any shade of brown, hazel/green, or blue depending on the strengths of the interactions.\n\nSo, yes... two blue eyed parents can produce a brown eyed baby.
645780
You can get it from following link.Best of luck in the seminar.\nhttp://www.mendelweb.org/Mendel.html
922905
There really is no essential difference in the way\nthe genes are inherited.  The difference is in how\nthey affect the offspring.  In polygenic inheritance\nthere are many gene pairs involved, each of which\nhas a small effect and the effects of each pair are\nadditive with the others.  Such genes control things\nlike height, weight, skin color, etc.  The genes in\nwhat is usually called Mendelian inheritance have a\nlarger and more noticeable effect.  Actually the\nexamples given in biology courses are usually\nover simplified.  The case of eye color is a good\nexample.  What is usually taught is that brown eyes\nare dominant and blue eyes recessive, but this is\ntrue only if all other things are equal, that is, there\nare no other genes affecting eye color to interfere.\nIn the fruit fly there are dozens of gene pairs that\naffect eye color, and probably as many in human\nbeings.  My father had blue eyes, my mother has\nbrown eyes.  I have never been able to decide\nwhat color my eyes are.  They are sort of blue\naround the edges, yellow more toward the center,\nwith a reddish brown spot in one of them.  Also\nwhat about eyes that are described as green, gray\nhazel, violet?
772472
This is pasage of biblography of my project\n\nGregor Mendel (1822-1884)\nSeung Yon Rhee \n--------------------------------------------------------------------------------\n\nThe theories of heredity attributed to Gregor Mendel, based on his work with pea plants, are well known to students of biology. But his work was so brilliant and unprecedented at the time it appeared that it took thirty-four years for the rest of the scientific community to catch up to it. The short monograph, Experiments with Plant Hybrids, in which Mendel described how traits were inherited, has become one of the most enduring and influential publications in the history of science. \n\nMendel, the first person to trace the characteristics of successive generations of a living thing, was not a world-renowned scientist of his day. Rather, he was an Augustinian monk who taught natural science to high school students. He was the second child of Anton and Rosine Mendel, farmers in Brunn, Moravia. Mendel's brilliant performance at school as a youngster encouraged his family to support his pursuit of a higher education, but their resources were limited, so Mendel entered an Augustinian monastery, continuing his education and starting his teaching career. \n\nMendel's attraction to research was based on his love of nature. He was not only interested in plants, but also in meteorology and theories of evolution. Mendel often wondered how plants obtained atypical characteristics. On one of his frequent walks around the monastery, he found an atypical variety of an ornamental plant. He took it and planted it next to the typical variety. He grew their progeny side by side to see if there would be any approximation of the traits passed on to the next generation. This experiment was "designed to support or to illustrate Lamarck's views concerning the influence of environment upon plants." He found that the plants' respective offspring retained the essential traits of the parents, and therefore were not influenced by the environment. This simple test gave birth to the idea of heredity. \n\nMendel's research reflected his personality. Once he crossed peas and mice of different varieties "for the fun of the thing," and the phenomena of dominance and segregation "forced themselves upon notice." He saw that the traits were inherited in certain numerical ratios. He then came up with the idea of dominance and segregation of genes and set out to test it in peas. It took seven years to cross and score the plants to the thousand to prove the laws of inheritance! From his studies, Mendel derived certain basic laws of heredity: hereditary factors do not combine, but are passed intact; each member of the parental generation transmits only half of its hereditary factors to each offspring (with certain factors "dominant" over others); and different offspring of the same parents receive different sets of hereditary factors. Mendel's work became the foundation for modern genetics. \n\nThe impact of genetic theory is no longer questioned in anyone's mind. Many diseases are known to be inherited, and pedigrees are typically traced to determine the probability of passing along an hereditary disease. Plants are now designed in laboratories to exhibit desired characteristics. The practical result of Mendel's research is that it not only changed the way we perceive the world, but also the way we live in it. \n\nI Hope u get ur answer for more halp contect on don_turtel@yahoo.com Whish u all the bet for homework-project
847447
Mendelian Genetics Problem Set  \nMendelian Genetics Assignment. The following problems are worth 2 points each. ... Suppose two of the offspring from problem 1 are crossed and produce 1000 ...www.humboldt.edu/~msw13/105_html/mendel
593850
Mendelian genetics predicts the probable result of genetic traits.  It assigns a dominate and recessive gene to each trait of a species that allows for variance, then calculates the possible match-ups of recessive and dominate genes.  The ratio of success of the dominate gene relates to its ability to produces a higher probability of result.  Mendelian genetics is never certain in its results, it shows the most probable result of a pairing.
556771
Men: Darwin, Mendel, Watson, Crick, Wallace, Carrollus Linneas\nWomen: Rosalind Franklin, Barbara McClintock,hmmm.... I should know more\nThose are ones I teach, you're on your own to find out what they did.
1062491
gregor mendel? i think that was him.\n\n*no the other person was right it is Aristotle. Mendel is the father of genetics.
478857
While the echoes of Darwin's book The Origin of Species reverberated, an Austrian botanist by the name of Gregor Mendel discovered the laws of inheritance in 1865. Not much heard of until the end of the century, Mendel's discovery gained great importance in the early 1900s. This was the birth of the science of genetics. Somewhat later, the structure of the genes and the chromosomes was discovered. The discovery, in the 1950s, of the structure of the DNA molecule that incorporates genetic information threw the theory of evolution into a great crisis. The reason was the incredible complexity of life and the invalidity of the evolutionary mechanisms proposed by Darwin. \nThese developments ought to have resulted in Darwin's theory being banished to the dustbin of history. However, it was not, because certain circles insisted on revising, renewing, and elevating the theory to a scientific platform. These efforts gain meaning only if we realise that behind the theory lay ideological intentions rather than scientific concerns. \nThe Desperate Efforts of Neo-Darwinism\nDarwin's theory entered into a deep crisis because of the laws of genetics discovered in the first quarter of the 20th century. Nevertheless, a group of scientists who were determined to remain loyal to Darwin endeavoured to come up with solutions. They came together in a meeting organised by the Geological Society of America in 1941. Geneticists such as G. Ledyard Stebbins and Theodosius Dobzhansky, zoologists such as Ernst Mayr and Julian Huxley, paleontologists such as George Gaylord Simpson and Glenn L. Jepsen, and mathematical geneticists such as Ronald Fisher and Sewall Right, after long discussions, finally agreed on ways to "patch up" Darwinism. \nThis cadre focused on the question of the origin of the advantageous variations that supposedly caused living organisms to evolve-an issue that Darwin himself was unable to explain but simply tried to side-step by depending on Lamarck. The idea was now "random mutations". They named this new theory "The Modern Synthetic Evolution Theory", which was formulated by adding the concept of mutation to Darwin's natural selection thesis. In a short time, this theory came to be known as "neo-Darwinism" and those who put forward the theory were called "neo-Darwinists".\nThe following decades were to become an era of desperate attempts to prove neo-Darwinism. It was already known that mutations-or "accidents" -that took place in the genes of living organisms were always harmful. Neo-Darwinists tried to establish a case for "advantageous mutation" by carrying out thousands of mutation experiments. All their attempts ended in complete failure.\nWhy Cannot Natural Selection Explain Complexity?\nThere is nothing that natural selection contributes to the theory of evolution, because this mechanism can never increase or improve the genetic information of a species. Neither can it transform one species into another: a starfish into a fish, a fish into a frog, a frog into a crocodile, or a crocodile into a bird. The biggest defender of punctuated equilibrium, Stephen Jay Gould, refers to this impasse of natural selection as follows; \nThe essence of Darwinism lies in a single phrase: natural selection is the creative force of evolutionary change. No one denies that selection will play a negative role in eliminating the unfit. Darwinian theories require that it create the fit as well.16\nAnother of the misleading methods that evolutionists employ on the issue of natural selection is their effort to present this mechanism as conscious. However, natural selection has no consciousness. It does not possess a will that can decide what is good and what is bad for living things. As a result, one cannot explain biological systems and organs that possess the feature of "irreducible complexity" by natural selection. These systems and organs are comp
1083600
I wonder...? Do you think such genes could be the product of ....GASP....EVOLUTION!\n\nMy belief in evolution, is PROOF it's true.\n\nHmmmm....\n\nOMG!\n\n I think, therefore, God doesn't exist!\n\nMove over Descartes, make room for ME!
708035
I can only answer number one.\nThe possible traits can be determined.  But there's no way of know the exact traits of the offspring unless the parents have either two dominate or two recessive genes with every specif trait.  For instance, using punnett square:\n \n----d----d\nD  Dd Dd\nD  Dd Dd\n\nAll the possible genotypes are the same.\nSorry I couldn't answer your other questions!
745993
There is a great animation that explains the experiments in detail (with pictures) on the Mendel site at http://www.mendel-museum.org/eng/1online/experiment.htm
1075511
what Mendel gave us was the "Law of Independent Assortment" and the "Law of Random Segregation".  Basically, that chromosomes behave in an independent manner when segregating from each other. (ie-when chromosomes are segregated to your gametes, the chromosomes your father gave you will not all go together, they will act independently of each other.)\nIn short, he gave us a way to predict what ratios of progeny to expect from parental generations. \n\nFor example, a dihybrid cross between PPSS and ppss will result in all F1 progeny PpSs, and if intercrossed, those F1 progeny will produce F2 progeny in a 9:3:3:1 ratio....\nso on and so forth.\n\nOf course these principles don't really apply with more complex human genetics...
809259
The law of segregation was formed by Gregor Mendel in the early 1860's.   The law basically says each organism contains two factors for each trait, or allele.  The factors segregate or separate in formation of gametes.   During meiosis, each gamete contains one factor for each trait.  When two games combine during fertilization, the offspring have two factors controlling a specific trait (one from mom, and one from dad).
151409
Mendel's First Law (Segregation) states that during gamete formation, each member of an allelic pair (the two 'copies' of a gene) separates from the other member and forms the "genetic supply" of the gamete. That is to say, as each allele is on one of a pair of homologous chromosomes, they will separate from each other during meiosis. \nThis may appear as very basic, but the realization that there were _pairs_ of "factors" (the term 'allele' did not exist in Mendel's time) that separated and then could combine was important because until then, it was thought that inheritance meant some kind of "blend" between elements from both parents. It was very difficult to figure out how, for instance, a flower color that skipped a generation and then appeared again could remain as a discrete element (the reasoning was: if I mix red and white plants, I'll get plants with rose color. Mixing rose with red or white should yield lighter or darker color, but not the originals).\n\nThe Second Law (Independent Assortment) can only be understood when studying _more than one_ allelic pair. The simplest case is the dihybrid cross, in which you analyze the outcome of a cross with respect to 2 different allele pairs. What Mendel found is that the segregation of the alleles of one allelic pair is independent of the segregation of the alleles of another allelic pair. That is to say, if one pair codes for flower color and the other for seed size, in the 2nd generation you will get all the possible combinations of these allele pairs. Remember we're talking of genotypes and _not_ phenotypes (that is, all the alleles will be present, but some will not be 'visible'). \nThe 2nd law works perfectly when the pairs of alleles in question are situated on different chromosomes. If the two pairs are on the same chromosome, there are more possibilities of certain combinations to occur; this is called genetic linkage.
841943
Mendel's laws predict that a monohybrid cross between any two heterozygotes would produce offspring in a 3:1 phenotypic ratio.  That is:\nAa  X  Aa = \n1 AA - Dominant Phenotype\n2 Aa - Dominant Phenotype\n1 aa - Recessive Phenotype\n\nSo, 3 Dominant : 1 Recessive\n\nNow for your two instances:\n\nA.\nIn the case of codominance we have two different dominant alleles and one recessive allele.  When both dominant alleles are present, the phenotype is different from that seen when either of the alleles is present alone (homozygous or heterozygous).  A classic example of codominance is that of blood types.  Type A and type B are both dominant phenotypes, type O is the recessive phenotype, and type AB is the codominant phenotype.\n\nBack to your question, lets say:\nA = dominant allele 1\nA* = dominant allele 2\na = recessive allele\n\nCrossing two heterozygotes: Aa X A*a results in\n1 AA* - codominant phenotype\n1 Aa - dominant allele 1 phenotype\n1 A*a - dominant allele 2 phenotype\n1 aa - recessive phenotype\n\nSo we have a 1:1:1:1 phenotype ratio, not Mendelian expected 3:1\n\nB.\nRecessive lethal alleles are a situation where the homozygous recessive genotype is lethal to the organism.  So if we cross two heterozygotes:\n\nAa X Aa \n\nWe get:\n\n1 AA - dominant phenotype\n2 Aa - dominant phenotype\n1 aa - lethal, so this offspring is never seen\n\nSo here all the offspring seen are of the dominant phenotype, again defying Mendel's predicted 3:1 ratio.\n\nHope this helps!