How many cycles in a PCR will be required for amplifying the genetic material to about one billion times?

30 cycles

The correct answer is Option (3)- 30 cycles

PCR (Polymerase Chain Reaction) is a technique that is used to make millions of copies of a sample DNA very rapidly. After the completion of each cycle, two copies of DNA samples are produced. So, From 1 DNA molecule we get 2ⁿ molecules after n number of cycles.

If the process of replication of DNA is repeated many times, the segment of DNA can be amplified to approximately billion times, i.e., 1 billion copies are made at the end of 30 PCR cycles. It is possible to generate 2ⁿ DNA molecules after ‘n’ number of cycles.

Therefore 2ⁿ = 2³⁰ =1,073,741,824

PCR is indeed a technique that can exponentially amplify a single copy of a specific DNA segment, generating thousands to millions of copies of that segment. The concept of 2ⁿ copies being produced after each cycle, where n is the number of cycles, is fundamental to understanding the power of PCR in DNA amplification.