Which method of reproduction is common to fungus, moss and fern ?

The correct option is Spore formation.

Step-by-step Explanation:

1. Understanding Spore Formation: Spore formation is a mode of asexual reproduction commonly observed in non-flowering organisms such as fungi, mosses (bryophytes), and ferns (pteridophytes). Under favorable environmental conditions, these organisms produce small, microscopic, single-celled or multi-celled reproductive units called spores.

2. Reproduction in Fungi: Fungi (such as Rhizopus, bread mold) produce sporangia, which contain spores. When these sporangia mature, they burst and release spores into the air. When spores land on a suitable moist medium, they germinate into new fungal hyphae.

3. Reproduction in Mosses (Bryophytes): Mosses reproduce asexually and sexually, but spore formation is the primary non-flowering reproductive mechanism where spores are developed within a capsule (sporangium). When released and dispersed by wind, they germinate into fresh protonema/moss plants.

4. Reproduction in Ferns (Pteridophytes): Ferns produce sori (clusters of sporangia) on the underside of their leaves (fronds). These sporangia produce spores that disperse in the environment to germinate into a independent free-living thalloid gametophyte called prothallus.

5. Comparison with Other Options:

- Budding: Common in organisms like yeast and hydra, not a common primary spore-based method across all three groups.

- Fragmentation: Occurs in algae like Spirogyra and some fungi, but not the characteristic reproductive method shared universally by mosses and ferns.

- Regeneration: A process of growing back lost parts, seen in organisms like Planaria, rather than a primary method of reproduction shared across fungi, mosses, and ferns.

Therefore, Spore formation is the method of reproduction common to fungi, mosses, and ferns.