Search results
Results From The WOW.Com Content Network
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.
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 antigens Aua and Aub, known as the Auberger antigens, were once thought to make up a separate blood group but were later shown to be Lutheran antigens arising from variations in the BCAM gene. 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 ...
He defined that group A blood agglutinates with group B, but never with its own type. Similarly, group B blood agglutinates with group A. Group C blood is different in that it agglutinates with both A and B. [9] This was the discovery of blood groups for which Landsteiner was awarded the Nobel Prize in Physiology or Medicine in 1930.
The genetic history of North Africa encompasses the genetic history of the people of North Africa.The most important source of gene flow to North Africa from the Neolithic Era onwards was from Western Asia, while the Sahara desert to the south and the Mediterranean Sea to the north were also important barriers to gene flow from sub-Saharan Africa and parts of Europe in prehistory.
Figure 2. Schematic illustration of maternal (mtDNA) gene-flow in and out of Beringia (long chronology, single source model). The Ancient Beringian (AB) is a human archaeogenetic lineage, based on the genome of an infant found at the Upward Sun River site (dubbed USR1), dated to 11,500 years ago. [1]
The term human blood group systems is defined by the International Society of Blood Transfusion (ISBT) as systems in the human species where cell-surface antigens—in particular, those on blood cells—are "controlled at a single gene locus or by two or more very closely linked homologous genes with little or no observable recombination between them", [1] and include the common ABO and Rh ...