'''Conjugation''' is a temporary union of two [[organism|organisms]] for the purpose of [[DNA]] transfer.<ref>Wile, Dr. Jay L. ''Exploring Creation With Biology''. Apologia Educational Ministries, Inc. 1998</ref>
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'''Conjugation''' is a temporary union of two [[organism|organisms]] for the purpose of [[DNA]] transfer.<ref>Wile, Dr. Jay L. ''Exploring Creation With Biology''. Apologia Educational Ministries, Inc. 1998</ref> Conjugation is most common in bacteria, and is a major factor in horizontal gene transfer. Conjugation between two cells of the same bacterial species involves a thin tube joining the cells and transferring DNA, but when two different species are involved the bacteria form a larger structure called a protoplast, where the cell walls form the bridge between the cells.