Read the scenario.
A graduate student is running a PCR reaction to study DNA extracted from an Egyptian mummy. The reaction does not seem to be working, so he checks his notes to see what he added to the reaction mix. He find the following list: mummy DNA, DNA polymerase, and DNA nucleotides.
What is the error in the setup?
He forgot to add DNA ligase.
He should have added DNA ligase instead of DNA polymerase.
He forgot to add primers.
He should have recognized that PCR cannot work on DNA extracted from a mummy.
I think the answer is A
You can only pick one?
He forgot to add primers would be my choice, DNA primers and not RNA primers with the latter being used in normal DNA replication in cells. There are no Okazaki fragments that need to be annealed, so no need for DNA ligase. Not being able to perform PCR on mummy DNA maybe an option, but I don't think it is the right answer choice.
This guy is right it is He forgot to add primers. I just took the test got it right.
Same, it's the right answer.
To identify the error in the setup, let's understand the purpose of the PCR reaction and the components needed.
Polymerase chain reaction (PCR) is a technique used to amplify specific regions of DNA. It requires several components, namely:
1. Template DNA (in this case, extracted from the Egyptian mummy)
2. DNA primers (short DNA sequences complementary to the target regions)
3. DNA polymerase (an enzyme that synthesizes new DNA strands)
4. DNA nucleotides (building blocks of DNA)
Based on the scenario, the graduate student added mummy DNA, DNA polymerase, and DNA nucleotides.
However, the error lies in the fact that the student did not add DNA primers. Primers are crucial for PCR as they define the regions to be amplified. DNA polymerase requires primers to initiate DNA synthesis.
Therefore, the correct answer is C: He forgot to add primers.
By carefully analyzing the setup and understanding the purpose and components of PCR, we can deduce the error made by the graduate student.