Question

What is a disturbance in the Hardy-Weinberg genetic equilibrium indicative of? Explain how it is caused. [3]

Answer 1

Disturbance in Hardy-Weinberg equilibrium is an indicator of change of frequency of alleles in a population, resulting in occurence of evolution. [0.5]
Five factors are known to cause Hardy-Weinberg equilibrium. They are : [0.5 mark for each factor]
(i) Gene flow or gene migration : When migration of a section of population to another place or population occurs, new genes are added to the new population.

(ii) Genetic Drift : When the same change occurs by chance.

(iii) Mutation: Any alteration of DNA sequences which results in consequent changes in genotype and phenotype.

(iv) Genetic Recombination: Generation of non-parental gene combinations.

(v) Natural Selection : Heritable variations enabling better survival helps the organism to reproduce and leave greater number of progeny.