Q.What is the biological significance of seed dispersal in flowering plants?

Without dispersal, seedlings would compete directly with the parent plant and with each other for the same limited resources.

Seed dispersal is the process by which seeds (or fruits containing seeds) are moved away from the parent plant, and it carries significant biological advantages for the species.

If all seeds simply fell and germinated directly beneath the parent plant, the resulting seedlings would be forced into intense competition with the parent -- and with each other -- for the same limited local resources: light, water, minerals and space. Such crowding would reduce the survival chances of most of the offspring. By carrying seeds away to new locations, dispersal spreads out this competition and improves the odds that at least some seeds will germinate in conditions favourable to their growth.

Dispersal also allows a species to colonise entirely new habitats and expand its geographical range over time, which is important for long-term survival -- for instance if local conditions at the parent's site later deteriorate (disease, resource depletion, disturbance), populations established elsewhere by dispersal can persist.

State the two main benefits directly: less competition/crowding near the parent, and the opportunity to colonise new ground.

Assuming dispersal is only about distance travelled -- its biological significance is really about the ecological outcome (reduced competition, new habitat access), not the mechanism or distance itself.