Lemurs are primates found on the island of Madagascar. At least 33 different species
of lemur are living on the island today. Scientists would like to know how closely
related the different species of lemur are.
In one study, the scientists collected tissue samples from several individuals of each
species. For each sample, they examined the DNA sequences of five different genes.
The polymerase chain reaction (PCR) was used to amplify the DNA in the samples.
Describe how to amplify a strand of DNA using the polymerase chain reaction
(PCR).
1. idea of isolation or preparation of a DNA sample (from
tissue) ;
2. description of reaction mix includes reference to DNA
polymerase and {(deoxy) nucleotides / primers / eq} ;
3. description of reaction mix includes reference to
{magnesium ions / buffer} ;
4. description of denaturation step to include appropriate
temperature e.g. 90 to 95 oC / eq ;
5. description of primer binding step [to include
appropriate temperature (40-70 oC)] / eq ;
6. description of extension step [to include appropriate
temperature (70-80 oC)] / eq ;
7. reference to an appropriate time for any one step eg 0.5
to 2 minutes ;
8. reference to suitable stated number of cycles e.g.15 to
35 ;