CBSE Class 12-science Answered

DNA is the genetic material in most organisms while only a few organisms have RNA as their genetic material because:

• RNA is highly reactive, labile and easily degradable. On the other hand, DNA is chemically less reactive and structurally more stable.
• RNA functions as an enzyme and is, therefore reactive and unstable while DNA does not get destroyed by heat.
• Uracil present in RNA is less stable as compared to thymine of DNA.
• RNA mutates at a much faster rate while DNA mutates at a much slower rate allowing the variations and characteristics to be inherited for generations.
• There is no repairing system in RNA. DNA has a repairing system in case of errors during replication of DNA.