Reproduction In Organisms

Binary fission is a mode of asexual reproduction in which a single parent divides into two nearly equal halves, each developing into a new individual, as described in NCERT Class 12, Chapter 1 (Reproduction in Organisms). Because only one parent is involved and the process relies on mitotic division, the offspring inherit an identical copy of the parental genome and are therefore genetically uniform clones of the parent. Greater genetic variation is incorrect, since variation is a hallmark of sexual reproduction where gametes from two parents fuse and recombination occurs. The presence of two parents is wrong because asexual reproduction is uniparental by definition. Formation of a zygote is also incorrect, as no fusion of gametes takes place during fission. A consistency check supports this: organisms like Amoeba and Paramecium that use fission produce populations of clones, which is exactly why asexual lineages show low genetic diversity. Hence genetic identity to the parent is the correct distinguishing feature.