Basically, spores are produced by non-flowering plants, while seeds are produced by flowering plants. A seed is the ripened ovule of a flowering plant. ----------------------- SEED This consists of an embryonic plant together with a store of food, all surrounded by a protective coat. The seed grows after the egg of a female plant has been fertilised by a male sex cell from a pollen grain. Some plants can grow a seed without input from a male cell. A seed is capable of growing into a new individual plant. SPORE A spore is a tiny reproductive body, made of either one or many cells, used by plants and fungi. Spores come in a great variety of forms. Spores separate from the parent plant or fungus, and develop into a new individual. In many plants, the spore develops into male or female sex cells which fuse during fertilisation to form a seed. In other plants and in fungi, the spores develop directly into a new individual, either vegetatively or sexually. Spores are unlike the seeds found in seed-plants, because they do not contain an embryo, and because they do not have much of a food reserve. Many resting spores can survive for long periods of time, and through unfavourable conditions such as extreme hot, cold or dry. http://www.naturegrid.org.uk/biodiversity/plants/glossqu.html ------------------ A spore is a biological term for a reproductive mechanism, usually haploid and unicellular, that is adapted for dispersion and surviving for extended periods of time in unfavorable conditions. The spore can develop into a new organism by dividing by mitosis without fusing with another cell, producing a multicellular gametophyte. Produced by meiosis by the sporophyte, the spore is considered a part of the life cycles of plants or algae with alternation of generations. The term derives from the ancient Greek word σπορα, meaning seed. Spores can be classified by their function, by their origin in the life cycle, or by their motility. A chief difference between spores and seeds as dispersal units is that spores have very little stored food resources compared with seeds, and thus require more favorable conditions in order to successfully germinate. Spores, therefore, are more resistant to harsh conditions and require less energy to start mitosis. Spores are usually produced in large numbers to increase the chance of a spore surviving. A fertilized seed contains the embryo from which a new plant will grow under proper conditions. It also contains a supply of stored food and is wrapped in the seed coat or testa. The stored food begins as a tissue called endosperm derived from the parent plant. Endosperm becomes rich in oil or starch, and protein. In some species, the embryo is imbedded in the endosperm, which the seedling will use upon germination. In others, the endosperm is absorbed by the embryo as the latter grows within the developing seed, and the cotyledons of the embryo become filled with this stored food. At maturity, seeds of these species have no endosperm. Some common plant seeds that lack an endosperm are bean, pea, oak, walnut, squash, sunflower, and radish. Plant seeds with an endosperm include all conifers and most monocotyledons (e.g., grasses and palms), and also e.g., brazil nut, castor bean. http://en.wikipedia.org/wiki/Seed http://en.wikipedia.org/wiki/Spore Side Note - The oldest Carbon-14 dated seed that was germinated into a viable plant was a 2,000 year old Date Palm seed, recovered from excavations at Herod the Great's palace on Masada in Israel; this Judean date palm seed was germinated in 2005.