Question

Which is a method of making many copies of DNA?

Answer 1

Answer:

D. Polymerase chain reaction

Explanation:

PCR is very percise; used to amplify or copy a specific DNA target from a mixture of DNA molecules by:

• two short DNA sequences (primers) are bind to start and end the DNA target
• perform the PCR; DNA templates is added to a tube that contains primers, free nucleotides, and the enzyme (DNA polymearse)
• it is mixed in a PCR machine that increases and decreases the temperature of the sample
• mixture is heated to seperate the double strnaded DNA templated into single strands
• mixture is cooled so the primers can bind to the DNA template
• the DNA polymerase will synthesize to new strands of DNA from the primers
• during synthesis, the end of the first cycle, the DNA molecule will consist of a new and old DNA strand
• PCR continues with added cycles to repeat the steps
• newly synthesized DNA segements serve as templates in later cycles; which can be copied over and over.