Assertion : The primary protenema of moss by death and decay of cells may break into fragments. Reason : Each fragment gives rise to leafy gametophyte.

Step-by-step solution

The haploid spores on germination gives rise to alga-like filamentous branched portion called primary protonema. This protonema develops buds, from which leafy gametophyte arises. Sometimes this primary protonema breaks up into small fragments accidentally and these fragments give rise to leafy gametophores.