Why are DNA primers an important ingredient in a PCR reaction?

DNA polymerase cannot start to copy a DNA molecule without a double-stranded starting point.
Primers create a double-stranded section of DNA.
DNA polymerase cannot start to copy a DNA molecule without a single-stranded starting point.
Primers create a single-stranded section of DNA.

C.) DNA polymerase cannot start to copy a DNA molecule without a single-stranded starting point.

PCR is typically used to amplify a specific gene, or portion of gene, so that we can study the

function of that gene or gene region. Primers are used to flank the region you want to amplify.

Each primer will amplify the gene sequence on both strands, creating a double-stranded gene

product.

product.

Explanation: what is the answer choose so i can pick one.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: