Deoxyribonucleic acid (DNA)

Deoxyribonucleic acid (DNA) is located in the nucleus of the cell and is the genetic material in the cell. In order for cells to undergo mitosis and meiosis, the cells must be capable of copying their DNA. In the assignment this week, we will review how this process of DNA replication occurs.

  1. DNA consists of two polynucleotide chains that run in opposite directions. This opposing orientation of the two strands makes them ___________.
  2. The building blocks of DNA are called nucleotides. Circle one nucleotide on the diagram above.
  3. Each nucleotide consist of three components ______, ___________, and __________. Label an example of each component on the diagram above.
  4. There are four nitrogenous bases in DNA. These bases are either single ring structures, called ______, or 2-ring structures, called ____.
  5. Complementary base pairs maintain the constant width of the double helix of DNA. Name the complementary base pairs of DNA.

Sample Solution

  1. An experiment conducted by ______________ demonstrated the DNA replication is _____, which means that the replicated DNA contains one new strand of DNA and one old strand of DNA.
  2. DNA replication occurs during the ________ phase of the cell cycle.
  3. In the image above, label the leading strand, lagging strand, primase, single strand binding proteins, and helicase. Draw an arrow to indicate the direction of replication.
  4. The lagging strand is synthesized continuously/discontinuously (Circle one). Why is it synthesized in this manner?
  5. Name the enzyme that performs each function.
    ___ Unwinds the DNA double helix
    _________Binds Okazaki fragments _________ Forms new DNA strands by adding complementary bases
    ___ Stabilizes the DNA molecule during replication
    ___ Makes a short section of RNA on the DNA template