recap

13.5 recap

Knowledge of the mechanisms of DNA replication led to the development of a technique for making multiple copies of DNA sequences.

learning outcomes

You should be able to:

  • Explain the purpose for each step in the PCR process.

  • Explain why PCR is useful in different research scenarios.

Question 1

What is the role of primers in PCR?

Primers in PCR bind to a short region of DNA and allow elongation of that strand of DNA when DNA polymerase is added along with nucleotide.

Question 2

One way to quickly identify an organism in the field is to use PCR: If there is amplification of a particular sequence, then the organism is identified. What is the basis for this test?

If a primer has a species-specific sequence—that is, a sequence of nucleotides complementary to a sequence unique to a certain organism—PCR will amplify a target DNA extracted from a field sample that has the unique sequence. This amplification will show that the organism with that sequence is present