Question

Ultimate source of genetic variations or the process which provides raw material for evolution is

• A. Sexual reproduction
• B. Meiosis
• C. Mutation
• D. Independent assortment

Answer 1

The correct option is C Mutation

Sexual reproduction is production of offspring by fusion of genetic information from two parents; the two underlying events of sexual reproduction are meiosis during gametogenesis and syngamy during fertilization. Crossover and independent assortment during meiosis and syngamy produce new combinations of genetic material. Meiosis is the reductional division wherein one DNA replication phase is followed by two consecutive nuclear divisions (karyokinesis) resulting in daughter cells carrying half the chromosome number as that of parental cell. Meiosis produces new combinations of genes by crossover and independent assortment. Independent assortment is segregation of factors for a trait independent of other factors during gamete formation followed by their random rearrangement in progeny thereby producing both parental and new combinations. Sexual reproduction, meiosis and independent assortment produce new combinations of existing genetic material but do not produce the new allelic that serve as raw material for evolution. Mutation is the change in chemical structure of gene at molecular level; it introduces new alternate forms of genes which impart a new trait to individual; thereby providing raw material for evolution. The correct answer is C.