Sudden heritable change in genetic material or character of an organism is known as mutation • Individuals showing these changes are known as mutants • An individual showing an altered phenotype due to mutation are known as variant • Factor or agents causing mutation are known as mutagens • This presentation gives you an idea about what is mutation , what causes mutation and it's types and effects in detail.Gene Mutations Sickle Shaped Red Blood Cells. ... revision guide because Jeevan's is a well-defined strategy; he shows you exactly what to do