Discuss the importance of genetic diversity in maintaining the resilience of fish populations to environmental changes and human impacts (6 marks) Question TWO a) Habitat restoration and connectivity in population conservation is faced with many challenges. Discuss (5 marks) b) Briefly explain the principle behind PCR highlighting its applications in fish conservation (7 marks) Question THREE Assume that length in Oreochromis variabilis (Victoria Tilapia) is polygenic varying from 30 cm to 50 cm. A 30cm purebred parent is crossed with another purebred 50 cm individual and the resulting F progeny is selfed producing 51 F2 progeny of continuous range of lengths of which 3 are 50 cm long. a) How many genes affect length in O. variabilis? (3 marks) b) Assuming that O. variabilis is diploid, how much length does each additive allele contribute? c) What lengths were expected in the Fi progeny? (3 marks) d) What is the distribution of lengths expected in the F2 progeny? (5 marks) Question FOUR Using appropriate examples, compare and contrast the genetic diversity of marine fish species with freshwater fish species (8 marks) (3 marks)