TLS Online TPP Program

#Question id: 2887


Which of the following reasons has led to the evolutionary selection of an extra methyl group in DNA?

#Unit 2. Cellular Organization
  1. Thymine is more stable than Uracil due to the absence of an extra methyl group attached to the 5’ position.

  2. Cytosine undergoes spontaneous deamination to yield Uracil, which repair enzymes cannot recognize as foreign to DNA.

  3. If the genetic material contained uracil, then uracil arising from cytosine deamination would go undetected by the surveillance systems that maintain the genome.

  4. Uracil has greater resistance to photochemical mutation, making the genetic material more stable.