what is the most common blood group in US? first one who answered this right wil get 10 points?

Most common: O+

Rarest: AB-

O+ is the most common.

Blood type, like hair, eye or skin colour, is inherited. Everyone inherits two 'blood type' genes one from their mother and one from their father. So you have two blood type genes, the combination of which gives you your blood group. The A and B gene are called 'dominant' genes as they always win over the O gene.

However, neither the A or the B gene are dominant over each other. If your blood group is A, you can only possess one of two combinations of genes A&A or A&O. If your blood group is B you also can have only one of two gene combinations, B&B or B&O. If you are a member of blood group O you can only have two O genes. If your blood group is AB your genes will be A&B.

But why, if O is so easily dominated, is it the most common blood group worldwide? The answer lies in the genes. A study carried out showed approximately seven out of ten people in this country carry at least one O group gene. So the chances of two O group genes being inherited from your parents becomes much higher than inheriting say two B's. That is why in this country, 47% of the population will be a member of the O blood group.

The O group is the oldest of the blood groups. Back in the Stone Age, everyone would have been O and today it's still the most common group in the UK, especially in the North of England. Over in Central and South America and the USA most people are O too. The fact that anyone can receive O blood reflects the fact that all other blood groups are derived from it.

Group A is the second oldest blood group, appearing around 25,000 - 15,000BC, when larger human settlements first appeared as farming developed. You'll find a lot of A in Central and Eastern Europe. It's the commonest group in Norway, Denmark, Austria, Armenia and Japan.

If you're looking for group B, then try the Chinese or Asian communities, where around a quarter of all people share this blood group. It emerged between 15,000 and 10,000BC as tribes migrated from Africa to Europe, Asia and the Americas and mingled with other populations.

The newest and rarest group, AB, only appeared between 1000 and 500 years ago, and is believed to have occurred as a response to the mixing of existing blood groups on a major scale. In Japan, China and Pakistan around 10% of the population boast this rarest of blood groups.

Population: O+ A+ B+ AB+ O− A− B− AB−

USA 38% 34% 9% 3% 7% 6% 2% 1%

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Population O+ A+ B+ AB+ O− A− B− AB−

USA 38% 34% 9% 3% 7% 6% 2% 1%

UK 37% 35% 8% 3% 7% 7% 2% 1%

Australia 40% 31% 8% 2% 9% 7% 2% 1%

Finland 27% 38% 15% 7% 4% 6% 2% 1%

Sweden 32% 37% 10% 5% 6% 7% 2% 1%

B+ is the most common as per the American Red Cross Blood Bank.

O+ is the most common.

type o positive is the most common blood type

O is the most common. Then A, then B, then AB.

O positive is most common. Also it is the "universal donor" because it it compatable with most others.

Good Blood Bad Blood Good Blood Bad Blood.

A positive

A2 most common. AB4 the most rare.