DNA template, RNA polymerase, dNTPs, Buffer solution

You are correct that the DNA template, i.e. the DNA you have already isolated, is important since it contains the target sequence to be amplified. You are also correct that you need a polymerase enzyme to synthesize the new strands, using the dNTPs (deoxynucleotide triphosphates), which are the building blocks for the synthesis of the new strand. You need to consider which polymerase enzyme you need though. The buffer solution is important to maintain the optimal pH and ionic strength for the activity of the polymerase. You also need to consider that the enzyme will need a starting point for strand synthesis. How will the polymerase know where to start to specifically amplify the transgene? Please consider these questions and try again.