Answer: Rh boold factor is determined by the presnce or absence of a particular erythrocyte protein
Explanation:
The Rh factor is an integral protein of the membrane of red blood cells (erythrocytes) and, by its determination, the blood type RH + or RH- is detected, -regardless of the types of groups known as 0, A, B and AB- .
People who are RH + are those who have this protein in their red blood cells, and people with RH - refer to those who do not have the protein.
The Rh factor (Rhesus) was discovered by Karl Landsteiner and Wiener in 1940.
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Answer:
2.5 billion years ago.
Explanation:
Evolutionary tree is constructed to understand the phylogeny and evolution relationship of the organism. The evolutionary tree is constructed by looking at the molecular and physiology of the different organisms.
The eukaryotes are more closely related to the archaea. Depending on the biochamical and molecular evidence is has been found that they share the common ancestor almost 2.5 billion years ago. This can also be deduced by the fossil evidence as well.
Thus, the answer is 2.5 billion years ago.