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Gene technologies allow the study and alteration of gene function allowing a better understanding of organism function and the design of new industrial and medical processes (A-level only)

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Question 5

In a forensic investigation to track the origin of confiscated ivory, conservation biologists isolate a highly variable locus containing a Variable Number Tandem Repeat (VNTR) from an African elephant (Loxodonta africana) DNA sample. This specific allele of the VNTR locus has a length of 24 base pairs.

a.

Describe how this target VNTR region can be excised and isolated from the rest of the genomic DNA sample.

[2]
b.

The polymerase chain reaction (PCR) is used to amplify this VNTR. Explain why it is essential to determine the base sequences of the regions flanking the target VNTR locus before PCR can begin.

[2]
c.

A forensic sample containing a single double-stranded DNA molecule of this 24-base-pair VNTR is amplified through 38 complete cycles of PCR. Calculate the total number of base pairs in all the generated VNTR molecules at the end of these 38 cycles. Show your working and give your answer in scientific notation to three significant figures.

[2]
d.

Describe how gel electrophoresis is used to separate the resulting DNA fragments of different lengths. State two physical properties of the DNA fragments that make this separation possible.

[2]

Gene technologies allow the study and alteration of gene function allowing a better understanding of organism function and the design of new industrial and medical processes (A-level only) Questions

  1. A Level
  2. /Biology
  3. /Gene technologies allow the study and alteration of gene function allowing a better understanding of organism function and the design of new industrial and medical processes (A-level only)