difference between negative and positive blood
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Answers:My dear John... NO !!! It's not the way you've mentioned in your last sentence...Blood is NOT..."blood"...There are (slight) differentiations in the various blood types...and quite complicated to explain with the allergens, etc. However here is some basic information on the subject: Normal red blood cells are recognized as self so we don t have antibodies against our own cells. However, we will have antibodies against the red blood cells of other people s blood if their cell surface carbohydrates are different from ours. This is the basis of ABO blood group and it s why we have to match blood types in a blood transfusion. The ABO blood group was discovered over one hundred years ago by Karl Landsteiner (Nobel Laureate: Karl Landsteiner). The biochemical basis was only elucidated in the 1970 s when the technology for examining the carbohydrate structure of glycoproteins was worked out. There s an allele of the A enzyme gene that involves only a very small number of mutations but the result is to switch the enzyme from one that transfers GalNAc to one that transfers galactose (Gal). The variant enzyme is called B enzyme (galactosyltransferase) and the B antigen structure has a terminal galactose (Gal) instead of a terminal GalNAc. If you are homozygous for the B allele on chromosome 9 then all of your red blood cells will have the B antigen oligosaccharide on their surface. You will not make antibodies against this structure because it s self. You also won t have antibodies against H-antigen for the reasons explained earlier. But you won t recognize A antigen as self so your antibodies will attack any foreign cells that come from people with the normal wild-type allele (A). People with blood type A will have antibodies against B antigen. They can receive blood from people with O blood type but they will reject blood from people with B blood type. You now have all the information you need to figure out who can give and receive blood from every possible combination of alleles: AA, AO, AB, BO, and OO. There are no known natural effects of these differing blood types. People with A, B, AB and O phenotypes do not differ in fitness in any major way that we have been able to detect. This suggests that the complete absence of the enzyme (null mutation) is neutral in the current human population and so is the switch from one form of the enzyme to another. (Suggestions that blood type determines susceptibility to some infections are common in the scientific literature. Most of them have not held up. The best correlation is a possible association between blood type O and susceptibility to cholera. This looks pretty good but the cause-and-effect relationship is still up in the air.) The ABO alleles seem to be segregating in the human population by random genetic drift. The O allele (non-functional enzyme) is the most common allele. The B allele is the least common probably because it arose more recently. Some Native American populations are homogeneous for the O allele; in those populations everyone has blood type O. (For maps of the frequencies A and B alleles see Distribution of Blood Types.) There are a total of 4 blood types, which are : O, A, B, and AB The : o-type is the most common of the 4 and is able to donate to all 4 types ! BUT: type A and type B can only donate to the AB-type ! Your Q. about the "pos./neg." part pertains to the "Rhesus factor" and some rare people have "rhesus factor negative", but most have "rhesus positive" ! All these factors are important for a blood transfusion because you can NOT give a "rhesus positive" person the blood from a "rhesus negative" person....and there's many more on the subject to be found in the internet under : www.blood-types.com Hope this was giving you some answers to your Q. - and- what the hell do you care about and "animal"(dinosaur's, etc.) anyway...??? That's a total different subject and has NOTHING to do with our "human blood" baby ! Send you all my love & care....Annette***
Answers:It's caused by the Rh factor. It's actually quite complicated to explain, involving 30 antigens of which D, C, c, E and e are the most important. Basically, if an individual has the Rh factor, they are blood type "positive" and if they don't have the Rh factor, then they're blood type "negative." You can try and decipher the exact meaning, but the basic explanation is probably all that's necessary.
Answers:The differance is that positive blood cells have Rh markers and negative does not.
Answers:it means that some people -with RH positive blood have an additional substance on theyr blood cells. The only problem is for women RH negative who have babies that are RH positive. In this case the mother's organism may develop antibodies that affect the pregnancy