Mutagenic nature of X-ray and UV-radiations was discovered by

The correct option is A Muller
George Beadle and Edward Tatum gave molecular definition of a gene while working on nutritional mutants in Neurospora. They exposed spores of the fungus Neurospora crassa to X-rays and other agents which damage DNA and cause alterations in DNA sequence and produce nutritional mutants. Muller used radioactivity to produce point mutations in the fruit fly Drosophila; male fruit flies were exposed to relatively high doses of radiation and were then mated to female fruit flies thereby induced more than 100 mutations. It was concluded that radioactive particles traverse through the chromosomes and randomly affect the molecular structure of individual genes, making them either non-functional or with altered function. Hardy Weinberg worked on allelic frequencies of population and suggested that the allele and genotype frequencies in a population remain constant under absence of factors responsible for evolution. Thus, the sum of all genotype frequencies can be represented as the binomial expansion of the square of the sum of allelic frequencies. Madam Curie coined the term radioactivity to refer ability of some elements to emit ionizing radiation or particles. Correct answer is C.