Question

36) Since dideoxy sequencing is based on the chain termination, why are normal dideoxyribonucleotides also included in the reaction? A) to enhance the chain termination ability of the deoxynucleotides B) to provide a substrate for RNA polymerase C) to produce a range of DNA synthesis products that terminate at every occurrence of a particular base D) to create DNA synthesis products long enough to allow running a gel

Answer 1

Answer:

The correct answer will be option-C

Explanation:

Sanger sequencing method or chain termination method is the method of sequencing used to sequence the nucleotides in DNA.

The Sanger method involves all the enzymes and sequence as in Polymerase chain reaction like DNA polymerase, primer and template DNA but they also contain dideoxynucleotides.

These dideoxynucleotides differ from the deoxynucleotides as the dideoxy nucleotides lack a hydroxyl group at 3' end which in normal nucleotide help bind the new nucleotides.

Since dideoxynucleotides are attached to the end of DNA fragments and thus prevent the binding of the new nucleotides thus terminates the reaction.

Thus, Option-C is the correct answer.