NEETZoologyBiotechnology - Principles and Processes
Read the following statements regarding the tools used in recombinant DNA technology: I. Exonucleases remove nucleotides from the ends of DNA. II. Endonucleases make cuts at specific positions within the DNA. III. DNA ligase facilitates the joining of DNA fragments by forming hydrogen bonds between them. IV. Taq polymerase is isolated from a thermophilic bacterium and extends primers during PCR. How many of the given
Options
- AOne
- BTwo
- CThree
- DFour
Correct answer
C. Three
Step-by-step solution
Statement I is correct as exonucleases remove nucleotides from the free ends of DNA. Statement II is correct as endonucleases make cuts at specific positions within the DNA duplex. Statement III is incorrect because DNA ligase joins DNA fragments by forming covalent phosphodiester bonds in the sugar-phosphate backbone, not hydrogen bonds (hydrogen bonds form spontaneously between complementary sticky ends). Statement IV is correct as Taq polymerase is a thermostable enzyme isolated from the thermophilic bacterium T