Generally, two complete copies of the material to be registered must be filed with the Register of Copyrights. For the duration of the life of the copyright owner plus 50 years. Facts and ideas cannot be copyrighted. Any author may write about any subject. Patents protect ideas which can be physically expressed in a machine, design, or process.
Trademarks protect the sign or brand under which products are made or distributed.
Copyright is divisible. The author, not the receiver. Generally, the employer, not the employee, unless there is a written agreement to the contrary that is signed by both the employer and employee. Yes, it s theoretically possible, and both would receive copyright protection. Note that an infringer does not have to quote lengthy passages.