Seeds need to be dispersed away from the parent plant to ensure the survival of the seedlings and the species as a whole. If seeds remain close to the parent plant, the seedling will have to compete with the parent for access to sunlight, nutrients and water.
Seeds are dispersed to avoid the overcrowding of a plant species in one locality and to ensure the geographic spread of a plant across relatively large areas. There are several mechanisms used for seed dispersal. Light seeds, such as dandelion seeds, spread across wide areas as the wind blows. Some seeds, such as coconut seeds, are waterproof and can be carried by a current of water over long distances. Some seeds have hooks that allow them to attach themselves to the fur of animals passing by, and they are then dropped at a location far away from the parent plant.
Usually, seeds are contained within a fleshy fruit that is edible to most animals. These seeds survive the passage through the gastrointestinal tract of the animal that consumed the fruit and are left behind by the animal along with some fertilizer to help the seed grow and survive. Some plants do not depend on external agents like wind, water or animals to disperse their seeds. Instead, their fruits have a mechanism that allows them to burst open with enough force to spread the seeds out away from the parent plant