Yeast, a cellular model. Yeast is a simple living being that functions in practically the same way as human cells. It is an historical subject of fundamental research to understand cellular and genetic phenomena. It is a representative model of all eukaryotic cells.
Covenant. An agreement, contract, or written promise between two individuals that frequently constitutes a pledge to do or refrain from doing something. The individual making the promise or agreement is known as the covenantor, and the individual to whom such promise is made is called the covenantee.
Bond Covenant. An agreement between the issuer and holder of a bond, requiring or forbidding certain actions of the issuer. Positive covenants require actions while negative covenants forbid them. The exact terms of a bond covenant must be written in the bond indenture.