Biology 9700 · AS & A Level · Principles of genetic technology
Principles of genetic technology — practice question
To sequence a gene’s DNA, the DNA is first denatured so that the two strands separate. Next, in the presence of a large supply of each of the four nucleotides, DNA polymerase copies the single-stranded DNA.
(a)[2]
Explain what controls the order of nucleotides in the newly replicated DNA strand.
(b)[2]
Using Fig. 3.1 and the information given, suggest why DNA polymerase did not insert the special nucleotide with a C base at the first position needing a C nucleotide.
(c(i))[1]
In what order will the fragments shown in Fig. 3.2 arrive at the light source and detector shown in Fig. 3.3?
(c(ii))[3]
Explain how gel electrophoresis separates these DNA fragments by size.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Base order in the original DNA strands” …