If a certain enzyme cuts a DNA strand in just one place, how many pieces of DNA do you expect to result?

1 Answer

  • Answer: Two pieces of DNA fragments will result if the enzyme is an endonuclease while only one piece of DNA strand and free nucleotides will result if the enzyme is an exonuclease.

    Explanation: Enzymes that cut DNA strands are called nucleases. There are two types of nucleases: exonucleases and endonucleases.

    Exonucleases cut or degrade DNA from end of the molecule, either in the 5'->3' or the 3'->5' direction removing nucleotides only from the 5' or the 3' end respectively.

    Endonucleases degrade or cut DNA strands at any site in the DNA strand, thus reducing it to smaller fragments.