a) Distinguish between mutations, mutants and mutagens. b) Give two causes of mutations.

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a) Distinguish between mutations, mutants and mutagens           Mutations are sudden, spontaneous and permanent changes; in an individual’s genetic material; Mutants are individuals who develop and exhibit unusual characteristics that were not previously present in the population; due to mutations; while mutagens are factors in the environment; that cause mutations to occur; 6 mks   

b) Give two causes of mutations            Irradiations such as gamma rays and ultra violet rays; chemical substances such as   mustard gas and other heavy metals (mercury, lead, asbestos); sudden extreme (high or low) temperatures; Max. 2 mks      c) Describe the causes and effects of chromosomal mutations      Deletion; refers to the absence of a portion of a chromosome; it results from breakage and       falling off of a portion of a chromosome; leading to loss of a group of genes that may have a disastrous effect on the development of an organism; Inversion; refers to reversal of normal sequence of genes in portion of a chromosome; occurs when a middle portion of a chromosome breaks, turns or rotates (inverts) through 180o and joins up again; this does not change the genetic constitution of the organism; but may bring into close proximity genes whose combined 

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