why is "O" blood the most common type of blood?\neven though it is recessive
202045
Dominance and recessive have nothing to do with frequency of an allele.  Basically, O is recessive because if you have an A allele and an O allele you will have type A blood, and if you have a B allele and an O allele you will have type B blood.  However, O is the most common type because most people don't have an A or a B allele, but just two O's.  The fact that A or B will be expressed if you have one doesn't make it more likely that you will have one.\n\nA and B are co-dominant (that's where the AB bloodtype comes from), but O is recessive to both A and B as it does not appear in the phenotype if an A or B allele is present.  Incidentally, these alleles are typically denoted I superscript A for A, I superscript B for B, and i for O, which reflects the dominance pattern as capital letters typically indicant dominant and lowercase indicate recessive.
446807
blood has hemoglobin in it which makes it like to stick together and to things....these are clots.... totally normal
418638
The women and the man would have a heterozygous geneotype\n\nThe woman's genotype would consist of a gene for B blood and for O blood.\nThe man's genotypes would consist of a gene for A blood and B blood.  \n\nSince O is a ressisve gene, A and B would dominiant the blood type for their children who could have an A, B or AB blood type.  \n\nFollowing a basic 2 x 2 Punnett square, the statistics of a child getting a homozygous B blood type would be 1/4; a AB blood type would be 1/4; for getting a heterzygous A or B blood type with a ressive O gene would be 2/4 or 1/2.
664383
no, the only time that blood type will be a concern is when the mother is Rh negative, and the father, Rh positive. The baby will be Rh positive like the father, because positive is dominant.\nThe problem with this is that if the baby's Rh positive blood mixes with the mother's Rh negative blood, the mother's blood will attack the baby's blood.\nThis looks bad, but doctors give Rh negative mothers shots before labor (and in any other situation where the blood might mix) to keep the mother and baby's blood from mixing.\nthat is the only genetic disadvantage that blood type can present.\nare congratulations in order?\nif so, CONGRATULATIONS!!!
384778
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!
603252
in old theoryit might seem that way, but not in real science. many genes and mutations can occurr without any generations having it or even skip generations. the structures of dna and genes have just been discovered to have millions of chromozones in each gene. enviroment has alot to do with genetics also. i have what is called factor v lieden. its a very rare mutation in my dna genes which causes blood clots all the time. at the va hospital, i found i was one of four known in the va system by the chief of staff to have it. they checked for genetics at first but no one in my family ever had a blood clot. just as in aids. there have been many children born from parents who were hiv and never got it. in your theory, the child could get nothing or the fathers 25 %. at what percent were the great, great grandparents. both 100 % or 50/50? the child could also get the great grandparents percentage which is the fathers. even with the mother at 75 and the father at 25. the child could get nothing, the fathers 25 percent or half of his or half of the mothers or half of both.
491287
The main blood groups of concern here are the ABO and Rhesus. \n\nThe rarest ABO group is AB which is found in ~ 3% of the UK population.  It actual frequency does vary depending on you racial background.\n\nThe Rhesus groups are generally classified as +'ve or -'ve.  You could see this written as DD or Dd for +'ve and dd for -'ve.  Rh + occurs in about 92% of the population and Rh- in the remaining 6%.\n\nThe rarest group would be AB, Rh- which would be found in about 1 in 500.\n\nHowever, the Rhesus system is more complex that simple +'v or -'v.   It can be broken down  into 6 or more Rh groups.  The rarest of these is written as Rh2Rh2 and occurs  in ~1%.     \n\nThere are many other blood groups.  Some can be important in transfusion but I will leave it here.
254294
No, a man with type AB blood can NOT have a type O child... The way blood types work is that A and B are surface markers on the red blood cells that are inherited. Type O means that there are NO surface markers. A and B types are codominant (i.e., both dominant) over type O.  So...if your father has an AB blood type, your brother MUST be either A or B or AB for this man to be his genetic father...he can NOT be O, no matter what your mother's blood type is.  The genetics are thus:\n\nIf Dad is AB and Mom is O: the possibilities for the children are AO or BO (type A or type B).\n\nIf Dad is AB and Mom is A: possibilities are A, B or AB.\n\nIf Dad is AB and Mom is B: possibilities are A, B or AB.\n\nIf Dad is AB and Mom is AB: possbilities are A, B, or AB.\n\nP.S.--Just because it's not possible for your father and brother to be related, that doesn't necessarily imply that your mother is a bad person...it just means she made a serious mistake in being unfaithful.  Don't let that influence your love for your brother.
407815
You can rule out certain blood types, but you can't know the exact one for sure.  For example, you can be sure the father is not either blood type O or B, but he could be A or AB.  The rh factor isn't as easy to figure out.
340814
my mom always told me that was just old blood.. i always get it in the beginning and end of mine\n\nand it's usually very light\n\nso it's probably just old blood!
505421
There are two things to consider:\n\n  In a blood transfusion, they don't always give you all the components of blood (the red blood cells, the platelets, the plasma, etc.).  In a normal transfusion, the person ONLY gets red blood cells and the plasma.  Neither of these has DNA...  Red blood cells do not have have a nucleus at all; that is why your body is constantly making new ones (and why you can keep giving blood without eventually "running out").  The plasma is just "fluid", so there's no nucleus there, either.  So, just getting a normal transfusion will not expose you to DNA.\n  Second, IF DNA somehow got in, I don't think there would be enough of it to cause any problem.  It would only be a small amount (because blood is largely plasma and cells) and, so, any DNA would not be common and, thus, probably easily handled by your body's defense system.  \n  Besides, DNA would only be a problem if it was in a cell where it can be translated and transcribed into gene products (proteins, etc.).  If it was just "floating around" in your blood, product wouldn't be made from it.  Also, the DNA would probably degrade fairly quickly.  DNA is sturdy, but blood has plenty of enzymes and different pHs that would most likely damage the DNA in some way.\n  So, that's my answer.  the second part was a little bit speculation, but I believe I'm right (I KNOW I'm right about the first part).
306898
The blood group of parents do not determine the sex of the child just the blood group of the child. Both my parents are O+ve, and i have got a brother. Its just the chromosomes X and Y that determines the sex in humans.
2936
Most blood transfusions are of packed red cells and not serum/platelets or white cells.  Red cells have no nuclei/genetic material.  Blood type and rH factor are important and mismatch can yield a type of rejection.  The white cells are ultimately "rejected"   In someone with an inactive immune system (chemo patient) the blood can attack the recepient!
69470
since A+B+O= 1 the frequencies are A=0.2 B=0.3 and O=0.5\nthe freqencies of each combination of alleles is\n\nAO are 2(0.2*0.5)= 0.2\nAA are 0.2*0.2= 0.04\nAB are 2(0.2*0.3)= 0.12\nBB are 0.3*0.3= 0.09\nBO are 2(0.3*0.5)= 0.3\nOO are 0.5*0.5= 0.25\n\nif they are looking for the phenotypes they are blood type A (AA+AO) 0.24, type B (BO+BB) 0.39, type AB is 0.12 and type O is 0.25\n\nand double check to make sure all the freqencies = 1
34557
blood brothers are an interesting concept - whilst the small amount of blood shared is unlikely to cause any transfusion reactions - it may transmit HIV or Hepatitis, but there is a strange case in Switzerland where a group of girls developed antibodies despite never having been transfused or pregnant/ it was eventually discovered that they had had a blood sisters pact and shared each others blood and had subsequently developed red cell antibodies to the blood they had mixed.
138869
Blood is red. Blood is ALWAYS red. There is a misconception that blood may at some point be blue because in biology text and models blood leaving the heart is frequently represented as blue because it has been oxygenated. Why blue for oxygen - it comes from the Greeks who realized there was oxygen in the sky and mistakenly thought oxygen gave the sky its blue color. There is also the common cliche "Blue blood" someone who is rich.
3472
(1) You can donate even without knowing your Blood Type.\n(2) Blood Group test is performed at almost every hospital. Result is obtained very shortly which allows you to know the type of yuor Blood Group.