Answer:
The correct answer are statements 2 and 4.
Explanation:
The polymerize chain reaction refers to a molecular technique that has an application in the amplification of the samples of DNA gathered from the crime scene. The small concentration of DNA sample can be replicated or reproduced via this technique, and post ten to twelve cycles a huge concentration of amplified DNA can be witnessed.
It is also used for preimplantation genetic diagnosis and genetic testing as the sample of DNA, that is, required to be implanted could be enhanced in huge number prior of performing implantation into the cell, and the testing of these samples of DNA can be performed with ease if it would be found in huge number.