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.
But since the local meat market was out of pork sausage, they used ground beef instead. Alas, another hamburger. The first account of serving ground meat patties on buns-taking on the look of the hamburger as we know it today-took place in 1904 at the St. Louis World Fair. But it was many years later, in 1921, that an enterprising cook from Wichita, Kansas, Walt Anderson, introduced the concept of the hamburger restaurant.