The three main stages of the PCR process are usually repeated around 30 times over several hours. Approximately how many copies of the target region of original DNA molecule are made during that time?

1073741824 copies of original DNA molecules will be made.

Explanation:

PCR represents the polymerase chain reaction which is used to amplify or produce copies of DNA molecules. It constitute of three main phases which are denaturation of sample DNA molecule, annealing of primer and extension of primer.

To calculate the number of copies produced in each cycle we use the formula 2ⁿ where n represents the number of cycles. So if three main stages of the PCR process are usually repeated around 30 times over several hours 2ⁿ becomes  2³⁰ which is equal to 1073741824. That Why if  pcr cycle is repeated 30 times it will produce almost 1 billion copies of original DNA molecule.

The number of cycles of PCR are dependent on number of DNA molecules present at starting and efficiency of primer extension and amplification. The reaction will continue after starting until one of the components of PCR become deficient.

a time line cause it goes from 685 to 978

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hope that !         : )