Why do we use "I" to represent the alleles for Blood Typing?
117358
The "I" stands for Immunoglobulin.\n\nQuote: For the ABO gene, the three alleles are the IA, IB and i alleles. We typically call these alleles "A," "B," and "O," but of course our rules for assigning symbols to alleles demand that all three be represented by some version of the same symbol. In this case, that common symbol is the letter "I," which stands for "immunoglobin."
228927
On the plasma membrane of the red blood cell (that's what the others said, and they're right).  \n\nThere is also a gene that some people carry that code for free A and B antigens in body fluids.  These people are called secretors, and the gene is dominant.\nFor example, I am a secretor.  I have determined my blood type by adding antibodies to my saliva, as well as by traditional blood tests.
797469
Your genotype determines your blood type before your born. There are three alleles or versions of the blood type gene: A, B, and O. Since everybody has two copies of these genes, there are six possible combinations; AA, BB, OO, AB, AO, and BO. In addition to the proteins (agglutinogens) existing on your red blood cells, other genes make proteins called agglutinins (a-GLOO-tin-ins) that circulate in your blood plasma. Agglutinins are responsible for ensuring that only the blood cells of your blood type exist in your body. People who have an AA genotype are said to have type A blood because the agglutinogen on their red blood cells has the enzyme activity associated with the A allele. It is important to recognize that people with the AO genotype also have the enzyme activity associated with the A allele, so they are also said to have type A blood. People with the BB and the BO genotypes are said to have type B blood. People who have the AB genotype have the enzyme activity associated with both the A and B alleles. These people have no agglutinins in their blood plasma.  In the case of blood type, both the AA and AO genotypes cause individuals to display the A blood type phenotype. Similarly, both the BB and BO genotypes cause individuals to display the B blood type phenotype. Individuals who are phenotypically type O or type AB have only one possible genotype, OO and AB, respectively. In different parts of the world, the fraction of individuals with blood type A, B, O, or AB differs. The frequency with which blood types are observed is determined by the frequency with which the three alleles of the ABO gene are found in different parts of the world (allele frequency). Variation in the allele frequency at the ABO gene reflects the social tendency of populations to marry and reproduce within a national, regional, or ethnic group. As people throughout the world intermingle to a greater extent, the distribution of the different blood types will become more uniform throughout the world. Hopefully that helps a bit!
563817
A, B, and O are the names of specific marker proteins on the blood cells.  A and B are with protiens and O is without.  Positive is indicative of yet another protein, and negative means you don't have it.  The body uses these proteins to identify the cell as 'self', to make sure it isn't a germ.  O negative blood can be accepted by anyone because it does not have any of the proteins that the body would call 'other' and attack.  It is the 'neutral' blood type. The big problem with this, though, is that people with O negative blood can only receive O negative because thier bodies would reject anything else.
757401
Yes, start with your blood type....for example 0+,\n\nnow check your siblings (brother & sisters)\nnow check your parents....and see who's blood everyone has!\n\nNow check your grandparents, and/or your aunts...if available.\nIt's amazing how many people do not know what their blood type is!
782918
Because of the "one drop rule" that has been ingrained in black people's history in America.  It says that if you have one drop of black blood, you are black.  Also, maybe they just identify more with the black side of them rather than the other side.  It's their prerogative.
948989
If there are two different alleles that cause different phenotypes, AND the phenotype of the het is indistinguishable from the phenotype of one of the homozygotes, then we say that that allele is completely dominant to the other, recessive allele.\n\nIncomplete dominance is usually used when the het has an intermediate phenotype due to haploinsufficiency, for instance, having one allele that codes for a working red pigment and one allele that codes for a broken pigment yields a pink flower that isn't making as much red pigment as the red homozygote.\n\nCo-dominance is when you can clearly see both gene products at the same time, like seeing blood cells with the A antigen and the B antigen.\n\n"Sickle-cell anemia illustrates that the terms dominance, incomplete dominance, and codominance are somewhat arbitrary. The type of dominance inferred depends on the phenotypic level at which the observations are being madeorganismal, cellular, or molecular. Indeed the same caution can be applied to many of the categories that scientists use to classify structures and processes; these categories are devised by humans for convenience of analysis."
269358
i think its because of a mutation in humans, and the mutations caused different blood groups to emerge.
416217
Im not gonna give you the answer but there is a really good site where you play the blood typing game then you should be able to figure it out for yourself.\nhttp://nobelprize.org/medicine/educational/landsteiner/readmore.html
222531
Why Do People Have Different Blood Types?\nFor Your Information \nThe types of proteins, glycoproteins and glycolipids found (or expressed) on the surface of red blood cells define blood types. In addition, blood types, or at least the genes responsible for them, are inherited. Karl Landsteiner described the original blood types - A, B, and O - in 1900 and doctors now recognize 23 blood group systems with hundreds of different types. Many of the blood type antigens (and the antibodies that react with them) have been discovered as a result of transfusion incompatibilities. Some of these molecules have additional functions that are at least as important as conferring compatibility (or lack of compatibility) on transfusion recipients however. The advent of sophisticated biochemisty and molecular biology has helped to characterize a number of these entities. Although it appears that the majority of the molecules are not essential for red cell function, some have specific functions on the red cell membrane such as allowing substances to enter and exit the red cell (transporters) or binding certain substances to the cell surface (receptors). \n\nFor some blood types, evolution and environmental selective pressures are clearly important for their persistence. For example, the Duffy blood type includes a receptor that allows certain types of malarial parasites to enter the red cell. Thus, in some malarial areas of Africa, populations with Duffy negative blood types have a distinct survival advantage because absence of the Duffy antigen provides a measure of protection against malaria. The percentage of people lacking the Duffy antigen is much higher in these locations than in areas not endemic for malaria. \n\nWe do not yet know the functions of the A and B blood group factors. (The O blood type is defined as the absence of A and B factors). They are most likely important, however, because they are expressed on many cells and tissues in addition to blood cells and circulate in the plasma as well. There are statistical differences in the frequency of certain malignancies that correlate with the ABO blood groups. Group A subjects have about a 20% greater risk of developing cancer of the stomack than do Group O subjects, for instance, whereas Group O subjects appear to have a greater risk of developing ulcers. The reasons are unclear. These disease susceptibilities are unlikely to confer a signficant survival advantage on a population, however, because (unlike malaria) they often occur beyond a subject's reproductive years. On the other hand, there is some evidence that Group O individuals are more susceptible than other blood type individuals to the agent that causes bubonic plague and Group A individuals are more susceptible to smallpox virus. These correlations may account for the increased frequency of the B gene in China, India and parts of Russia, which suffered epidemics of both of these diseases. Infectious organisms that carry A and B like antigens may have indeed played a role in the somewhat different distribution of blood types worldwide. \n\nFinally, a number of myths exist about blood types. Claims have been made that Group A people have the worst hangovers, Group O people the best teeth and Group A2 people the highest IQs, for example. With these and other purported associations, both the scientific basis and evolutionary significance are limited at best.
677018
8\nhttp://en.wikipedia.org/wiki/Blood_groups
719238
blood types such as the ABO system and MNS system.
427028
The differences in human blood are due to the presence or absence of certain protein molecules called antigens and antibodies. The antigens are located on the surface of the red blood cells and the antibodies are in the blood plasma. Individuals have different types and combinations of these molecules. The blood group you belong to depends on what you have inherited from your parents.\n\nThere are more than 20 genetically determined blood group systems known today, but the AB0 and Rh systems are the most important ones used for blood transfusions. Not all blood groups are compatible with each other. Mixing incompatible blood groups leads to blood clumping or agglutination, which is dangerous for individuals.\n\nNobel Laureate Karl Landsteiner was involved in the discovery of both the AB0 and Rh blood groups.\n\nCheck the full text\n\nhttp://nobelprize.org/medicine/educational/landsteiner/readmore.html
420530
An allele.  Alleles can be dominant or recessive.
433477
here you go:\n\nWhat is allele?\n\nIts a good sentence
639406
When Mendel began to scientifically analyze "heredity", he concluded that each parent (mother + father) donates an "allele" for a characteristic (trait) in question.\n\nA lettering system was used: Capital letters indicated that the allele is DOMINANT; lower-case letters indicate that the allele is RECESSIVE.  This is the case for 22 of the 23 chromosome pairs in humans.  The 23rd pair are called the sex chromosomes.  Females (mother) always donate an "X" allele; fathers can donate either an "X" or a "Y" allele.\n\nIf a person's genotype for their sex is "XX", this means two things.  1: Both X's are the same (in other words, X and X are identical).  Identical alleles are called HOMOZYGOUS.  2: A human who is "XX" is female.\n\nA human who is "XY" is male.  "X" allele and "Y" allele are DIFFERENT.  Thus, they called HETEROZYGOUS.  We refer to men as being "heterozygous" in that a male's SEX alleles, 'X' and 'Y' are different.\n\nLet us say "B" is the dominant allele for brown eyes, and "b" is the recessive allele that can result in blue eyes.  A person who is "Bb" is heterozygous (B is a different allele than b).  A person's who genotype is Bb is likely to have brown eyes.  A person who is "BB" is HOMOZYGOUS (1st B is identical to the 2nd B) and will definitely have brown eyes.  A person who is "bb" is HOMOZYGOUS (1st allele 'b' is identical to the 2nd allele, 'b') for the recessive allele; this person will have blue eyes.
673764
first all blood has 3 genes a,b,o.  A and B are both dominant while o is recessive.  A person with A phenotype blood can have a genotype of AA or AO.  Same with the B phenotype blood except only with B.  AB phenotype is the same as the genotype AB and same goes for O.  OO phenotype can only be seen as OO genotype.  When people do the nasty and mate each one type is paired with another.  For example an AO phenotype person and an B0 phenotype person can have a babies as AB,AO,BO,OO.  The punnet square all depends on two peoples blood type and the possibilities of the childs when they mate, you cannot make a square of an individual.