The three main stages of the PCR process are usually repeated around 30 times over

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.

The law of multiple proportions states that if two elements form more than one compound between them, the masses of one element combined with a fixed mass of the second element form in ratios of small integers. Consider two separate compounds are formed by only carbon and oxygen.