Greek also had an alpha copulativum, a- or ha-, expressing union or likeness, which is the a- expressing "together" in acolyte, acoustic, Adelphi, etc. It is from PIE root *sem- (1) "one; as one, together with."
"sexual protoplasmic body," 1880, coined 1878 by German cytologist Eduard Strasburger (1844-1912), the widespread attribution of the word's coinage to Mendel being apparently erroneous. From Greek gamete "a wife," gametes "a husband," from gamein "to take to wife, to marry," from PIE root *gem(e)- "to marry" (source also of Greek gambros "son-in-law, father-in-law, brother-in-law;" Sanskrit jamih "brother, sister," jama daughter-in-law;" Avestan zama-tar "son-in-law;" Latin gener "son-in-law"). See also -gamy. The seventh month of the ancient Attic calendar (corresponding to late January and early February) was Gamelion, "Month of Marriages." Related: Gametal.