| The diagram shows the changes in temperature of the reaction mixture during the Polymerase Chain Reaction (PCR). |
 |
| The main events during one cycle of the reaction are listed belowon |
| I. Binding of RNA primers |
| II. DNA synthesis |
| III. Separation |
| Which combination correctly matches each event with the temperature in the reaction mixture? |
A) X-I, Y-II, Z-III
B) X-II, Y-III, Z-I
C) X-III, Y-I, Z-II
D) X-III, Y-II, Z-I
Correct Answer: C
Solution :
| There are three major steps in a PCR. |
| Step 1: Denaturation The thermal cycler heats the mixture of primer and DNA fragment to about\[95{}^\circ C\]. Hydrogen bonds holding the double-stranded DNA fragment break and the double-stranded DNA separates and dissociates into single strands. |
| Step 2: Annealing of primers The solution is allowed to cool to\[37{}^\circ C\]. As it cools, primers base pair with complementary sequences at the 3' end of the single-stranded DNA. |
| Step 3: Primer extension The thermal cycler then raises the temperature to\[72{}^\circ C\]. Using the primer, the polymerase synthesises the rest of the fragment resulting in the new strand of DNA. |
You need to login to perform this action.
You will be redirected in
3 sec
