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Blood type (also called a blood group) is a classification of blood, based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins , carbohydrates , glycoproteins , or glycolipids , depending on the blood group system.
The phenotypes Lu(a+b−) and Lu(a+b+) are found at various frequencies within populations. The Lu(a−b+) phenotype is the most common in all populations, whereas the Lu(a−b−) phenotype is uncommon. Though present in the fetus, it is seldom the cause of erythroblastosis fetalis or of transfusion reactions.
A complete blood type would describe each of the 45 blood groups, and an individual's blood type is one of many possible combinations of blood-group antigens. [3] Almost always, an individual has the same blood group for life, but very rarely an individual's blood type changes through addition or suppression of an antigen in infection, malignancy, or autoimmune disease.
The "O" blood type (usually resulting from the absence of both A and B alleles) is very common around the world, with a rate of 63% in all human populations. [135] Type "O" is the primary blood type among the Indigenous populations of the Americas, particularly within Central and South American populations, with a frequency of nearly 100%. [135]
The question was resolved only in 2010, when it was established that Eurasian populations exhibit Neanderthal admixture, estimated at 1.5–2.1% on average. [15] The question now became whether this admixture had taken place in Europe, or rather in the Levant, prior to AMH migration into Europe.
Haplogroup R1b probably originated in Eurasia prior to or during the last glaciation. It is the most common haplogroup in Western Europe and Bashkortostan ( Lobov 2009 ). It may have survived the last glacial maximum , [ 19 ] in refugia near the southern Ural Mountains and Aegean Sea .(
The Atlas is a World Map, that is, world map and regions of the Earth with the various peoples who live there. The work was done at the request of Prince John, son of Pedro IV, desirous of a faithful representation of the world from west to east. 12 sheets form the world map on tables, linked to each other by scroll and screen layout.
The ABO blood group system is used to denote the presence of one, both, or neither of the A and B antigens on erythrocytes (red blood cells). [1] For human blood transfusions , it is the most important of the 44 different blood type (or group) classification systems currently recognized by the International Society of Blood Transfusions (ISBT ...