Final answer:
Pairing C, Gene silencing: production of subunit vaccines, is the one that does NOT match. Gene silencing is used to downregulate gene expression, not for producing subunit vaccines.
Step-by-step explanation:
The pairing that does NOT match between recombinant DNA techniques and their applications is C. Gene silencing: production of subunit vaccines.
Here's why the other pairings match:
- A. Gene therapy: The technique of gene therapy involves replacing a defective gene with a functioning one to treat or cure genetic diseases, confirming that pairing A is correct.
- B. PCR: The Polymerase Chain Reaction (PCR) technique is used to amplify, or create many copies of, a specific segment of DNA. Therefore, pairing B is accurate.
- D. Genetic modification of yeast: Yeast can be genetically modified to produce human proteins such as insulin, which demonstrates the correct use of recombinant DNA technology in the production of purified insulin, making pairing D correct as well.
However, gene silencing, which often involves RNA interference, is more commonly associated with downregulating or stopping the expression of specific genes, not with the production of subunit vaccines. Therefore, pairing C does not match. Subunit vaccines typically involve the use of a fragment of the pathogen (like a protein subunit) to stimulate an immune response without the need for a living pathogen.