1.1. Manual methods of sequencing use gel electrophoresis as a method of separating out the DNA fragments. Figure 1 shows the results after electrophoresis was carried out on a sample of DNA fragments.

 Figure 1

Identify and explain one property of the DNA fragments which allows them to be separated using gel electrophoresis as shown in Figure 1.

1.2. In recent years, new automated DNA sequencing methods have been developed.

Suggest one benefit of automated DNA sequencing methods compared to the original manual methods.

1.3. The epigenome is all of the chemical groups added to an organism’s DNA that affect gene expression without altering the base sequence. The proteome of an organism is influenced by the epigenome of the individual.

Describe how the epigenome affects the proteome of an organism.

1.4. Genome sequencing has provided the tools to allow scientists to screen people for alleles which may indicate predisposition to a particular health issue.

Suggest one disadvantage of screening people for alleles such as these.