1. DNA is double stranded. This means that when the strands separate during replication, both strands can be used as templates to produce two new double stranded DNA ,each containing one of the original strands (as shown on diagram). 2. DNA consists of complimentary nucleotides. The chemical structure of nucleotides means that they only bind to the complimentary nucleotide via hydrogen bonding. This means that when bases are exposed, only the correct nucleotide can bind, conserving the information in the original DNA Top tip: state the feature first in a simple sentence for your own and for the markers clarity. Then go on to explain your point in a new sentence.