question_answer 56)

  Name the law that states that the sum of allelic frequencies in a population remains constant. What are the five factors that influence these values?

Answer:

  Hardy ?Weinberg Principle states that the sum of allelic frequencies in a population is stable and is constant  from generation to generation, i.e., the gene pool (total genes and their alleles in a population remains constant. This is called genetic equilibrium. The sum total of all the allelic frequencies is Five factors that influence these values are (i) Gene Migration or Gene Flow When migration of a section of population to another place occurs, gene frequencies change in the original as well as in the new population. New genes/alleles are added to the new population and these are lost from the old population. There would be gene flow if this gene migration, happens multiple times. (ii) Genetic DriftIt refers to the elimination of the genes of certain traits when a section of population migrates or dies of natural calamity. It is an evolutionary force operating in small populations whereby gene frequency changes by chance leadings to loss of some genes or gain of others irrespective of their selective advantages or disadvantages, (iii) Mutation The sudden heritable change which is directionless in gene is called mutation '.It alters the genetic frequency or genetic makeup of an individual. (iv) Genetic Recombination This phenomenon occurs during gamete formation when chromosomes pass from parents to offsprings which show new combination of characteristics. (v) Natural SelectionIt is a phenomenon by which some members of population having traits that enable them to grow and reproduce at higher rater are favoured .Hence, they leave more surviving offspring in the next generation than others.