The biological basis for assigning all human beings into a singe species is that there so many, even tons of living organisms living on earth. These organisms differ in their external and internal organs and so to differentiate them from them, they are being classified into kingdoms then classes then phylums then family.
Had to look for the options and here is my answer. The answer that fits the blank is SPATIAL NEARNESS. When we say spatial nearness, this refers to small distance or closeness and marital homogamy becomes a choice in marriage. <span>Marital homogamy refers to the relationship wherein someone marries another who are of the same sociological status.</span>
B) 15-22 years old is the age range that fit the skull
It has11 protons and neutrons atomic number=11 mass=22