1. (a)

State three ways in which the structure of messenger DNA differs from RNA.

  • DNA double stranded, not single
  • thymine, not uracil
  • deoxyribose, not ribose
  • longer
(any 3)

Explain why exact replication of DNA is necessary in living organisms.

  • to have, complete/ same/ correct, genetic information / code
  • so appropriate / the right proteins coded for by DNA

 Name the enzyme involved in replicating the DNA molecule.

  • DNA polymerase