Black Holes: Facts, Theory & Definition. Black holes are some of the strangest and most fascinating objects found in outer space. They are objects of extreme density, with such strong gravitational attraction that even light cannot escape from their grasp if it comes near enough.
Chemigation is the injection any chemical such as nitrogen, phosphorus or a pesticide into irrigation water and applied to the land using the irrigation system. The proper use of chemigation is recognized as a Best Management Practice (BMP) for irrigated agriculture.
Conjugation is the process by which a plasmid is transferred from an F+ cell into an F-cell. The F factor in the F+ cell contains genes which express pili for attachment, and special membrane proteins for the transfer complex. Some conjugative plasmids carry drug resistant strains--a big problem for hospitals.