(genetics) a virus or other agent that is used to deliver DNA to a cell | the semantic role of the animate entity that instigates or causes the happening denoted by the verb in the clause |
a variable quantity that can be resolved into components | an active and efficient cause; capable of producing a certain effect |
any agent (person or animal or microorganism) that carries and transmits a disease | a businessman who buys or sells for another in exchange for a commission |
a straight line segment whose length is magnitude and whose orientation in space is direction | a representative who acts on behalf of other persons or organizations |
| any agent or representative of a federal agency or bureau |
| a substance that exerts some force or effect |