Vulcan blood is presumed to be green in color , the explanation for this ( first definitely advanced in the installment  Obsession ,  from the original program ) being that the oxiferous ( oxygen-carrying ) protein hemoglobin , in Vulcan blood cells , is chemically based on the element copper , rather than the element iron as is the case with ...
SECONDARY GROUPS The term secondary group has come into use in sociology to describe any group which lacks one or more of the elements that go together to characterize a primary group. In general, a secondary group is composed of individuals who lacks strong emotional ties one another.. (end of quotation) .
The main branches of sociology are as follows: 1  Theoretical Sociologist. It includes micro theory or small/middle/large theory. 2  Historical Sociology. It is the study of social facts and social groups. 3  Sociology of Knowledge. The newly emerged branch of sociology indicates that our knowledge is the product of social phenomena.  Criminology.