Final answer:
The incorrect pairing is 'D. Gene silencing; production of subunit vaccines' as gene silencing is not directly used to produce subunit vaccines, which are typically created with recombinant DNA technology.
Step-by-step explanation:
The pairing that does NOT match is 'D. Gene silencing; production of subunit vaccines'. Gene silencing is a method used to reduce or stop the expression of specific genes, often through RNA interference (RNAi) or related mechanisms. While this has applications in treating viral infections and studying gene functions, it is not directly employed in the production of subunit vaccines. Subunit vaccines are typically produced by isolating a specific protein or part of the pathogen (antigen) that can stimulate an immune response and are commonly produced through recombinant DNA techniques, not gene silencing.
Recombinant DNA technology is used for the genetic modification of organisms such as yeast to produce substances like insulin. Gene editing, specifically using CRISPR-Cas9, enables the correction of genetic mutations at precise locations within the genome. PCR is a technique used to make many copies of a specified DNA segment, amplifying the genetic material to levels that are easier to study or manipulate.