Calculate the maximum change in temperature that the reaction tube experiences during one cycle of PCR. (1) the function of PCR. (1) Describe what happens to the DNA during stage X. (1) Short sections of DNA called primers are involved in Stage Y. State what happens to these primers during Stage Y. (1) Suggest why the temperature is increased during Stage Z. (1) (i) A forensic scientist discovered a tiny spot of blood at a crime scene. A sample taken from this spot contained 100 molecules of DNA. The sample underwent PCR cycles for 40 minutes Use the graph to calculate how many molecules of DNA would be present after this time. (1) (ii) What process would then allow an individual to be identified from the DNA? (1) Photographic film consists of a clear sheet of plastic coated with chemicals that give it a dark appearance. The chemicals are stuck to the plastic by the protein gelatine. An investigation was carried out using the photographic film and the enzyme trypsin which digests protein. A piece of photographic film was placed in a test tube containing a solution of trypsin, as shown in Figure 1 below. The time taken for the film the turn clear was measured. The procedure was then repeated using different concentrations of trypsin solution. The results of the investigation are shown in Table 1 below.
Calculate the maximum change in temperature that the reaction tube experiences during one cycle of PCR. (1) the function of PCR. (1) Describe what happens to the DNA during stage X. (1) Short sections of DNA called primers are involved in Stage Y. State what happens to these primers during Stage Y. (1) Suggest why the temperature is increased during Stage Z. (1) (i) A forensic scientist discovered a tiny spot of blood at a crime scene. A sample taken from this spot contained 100 molecules of DNA. The sample underwent PCR cycles for 40 minutes Use the graph to calculate how many molecules of DNA would be present after this time. (1) (ii) What process would then allow an individual to be identified from the DNA? (1) Photographic film consists of a clear sheet of plastic coated with chemicals that give it a dark appearance. The chemicals are stuck to the plastic by the protein gelatine. An investigation was carried out using the photographic film and the enzyme trypsin which digests protein. A piece of photographic film was placed in a test tube containing a solution of trypsin, as shown in Figure 1 below. The time taken for the film the turn clear was measured. The procedure was then repeated using different concentrations of trypsin solution. The results of the investigation are shown in Table 1 below.
Unit-1-AB-Test.docx