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TLS Online TPP Program

#Question id: 18835

Polymerase chain reaction (PCR) utilizes a heat-stable polymerase (Taq polymerase) to amplify DNA strand. Which of the statement best describes why thermo-stable polymerases are required for PCR?

#Unit 13. Methods in Biology
  1. PCR needs thermal cycling, and the Taq polymerases can be inactivated since they are not needed during the low-temperature steps. 
  2. Heat stable (Taq) polymerase do not break the dsDNA unless the temperature is very high. Therefore a heat-stable (Taq) polymerase is required.
  3. PCR needs thermal cycling, and the heat-stable (Taq) polymerases will not denature to lose efficacy in DNA polymerization during the high temperature (95oC) step. 
  4. The interaction between divalent cations and DNA polymerase is much efficient during high-temperature steps. Thus PCR requires heat-stable DNA polymerase.
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TLS Online TPP Program

#Question id: 13221

#Unit 6. System Physiology – Plant

There are two main types of water-transporting cells in the Xylem,
TLS Online TPP Program

#Question id: 17073

#Unit 12. Applied Biology

Hypoxanthine is converted into guanine by the enzyme HGPRT an enzymes of the salvage pathway. What does HGPRT stands for?
TLS Online TPP Program

#Question id: 10307

#Unit 6. System Physiology – Plant

pyruvate dehydrogenase (PDH) complex requires many enzymes for their functions, which of the following enzyme are not the part of this complex?
TLS Online TPP Program

#Question id: 21392

#Unit 12. Applied Biology

In which one of the following bulk synthesis are easy?
TLS Online TPP Program

#Question id: 7128

#Unit 5. Developmental Biology

Imagine that in an attempt to get the â-globin gene to be expressed in B-cells, the transcription factors (GATA-1 and GATA-2) known to control the â-globin gene in erythrocytes were introduced into B-cells, yet the â-globin gene was not expressed. What is a likely explanation for this result?