6 3 During the civil war in Mozambique, from 1977 to 1992, 90% of the African elephants were killed for the ivory in their tusks. Since 1992, the elephant population in Mozambique has increased. The photograph shows a group of elephants in Mozambique. Elephant without tusks Elephant with tusks © ALEXANDER JOE/Staff/Getty Images A study of an elephant population in Mozambique was carried out in 2017. The elephants studied were all born before 1992. The table shows the number of elephants with and without tusks. Elephants Number of elephants with tusks 98 without tusks 102 Turn over 7 (a) The presence of tusks is controlled by a single gene. The allele for tusks is known to be dominant. The frequency of alleles in a population can be determined using the Hardy‑Weinberg equation. Calculate the frequency of the dominant and recessive alleles in this population. Give your answer to 2 decimal places. (3) Frequency of the dominant allele .............................................................. Frequency of the recessive allele .............................................................. 8 (b) In most African elephant populations, 2% to 4% of elephants do not grow tusks. (i) Explain why the percentage of elephants without tusks in Mozambique will probably increase in the future. 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(ii) Describe how the Hardy‑Weinberg equation can be used to provide evidence for changes in the elephant population in Mozambique. 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(Total for Question 3 = 8 marks) Turn over 9 BLANK PAGE