Ciliate conjugation is a sexual phenomenon that results in genetic recombination and nuclear reorganization within the cell. In most ciliate groups, however, the cells separate after conjugation, and both form new macronuclei from their micronuclei.
Before the bun, hamburgers are said to have been served between two pieces of bread. In fact, a ground beef patty was known as Hamburger steak (first mentioned in an American cookbook in 1891); when this was put between bread or in a bun it was called a Hamburger sandwich.
The Historical Society explains that Nagreen named the hamburger after the Hamburg steak with which local German immigrants were familiar. Louis Lassen of Louis' Lunch, a small lunch wagon in New Haven, Connecticut, sold its first hamburger in 1895.