1.1. Describe the main role of the molecule, DNA.

1.2. State one nucleic acid; DNA, or RNA, which never leaves the nucleus in a eukaryotic cell. Ignore the events of the stages of mitosis. 

1.3. The presence of nucleotides has been put forward as a definition of whether an entity constitutes a form of ‘life’. Name the three main components of all nucleotides. 

1.4. Figure 1 shows the way in which nucleotides join together to form the backbone of the DNA double helix.

Figure 2

Name the bond that joins the nucleotides together to form this backbone.  The bond is labelled as bond X in Figure 1.