How does a gymnosperm prevent itself from pollinating the same tree

1. A seed contains a well-developed multicellular young plant with embryonic root, stem, and leaves already formed, whereas a plant spore is a single cell.

2. The parent plant protects and supports the young plant in the seed during its development; spores do not receive such attention.

3. A seed contains a food supply. After germination, in which the young plant begins to grow and establish itself as an independent plant, it is nourished by food stored in the seed until it becomes self-sufficient. Because a spore is a single cell, minimal food reserves exist to sustain the plant that develops from a germinating spore.

4. The seed is protected by a multicellular coat. Seeds (and spores) can survive for extended periods of time at reduced rates of metabolism and then germinate when conditions become favorable.

5. Seeds and seed plants have been intimately connected with the development of human civilization. From prehistoric times, early humans collected and used seeds for food. The food supply stored in seeds contains proteins, oils, carbohydrates, and vitamins that are nourishing for humans as well as for germinating plants.

6. Because seeds are easy to store, provided they are kept dry, humans could collect seeds during times of plenty, and save them for times of need. Few other foods can be stored as conveniently or for as long as seeds.

7. The elimination of the necessity of water to transport the sperm grom the microgametophyte to the megagametophyte for fertilization to occur.

8. This development made it possible for seed plants to complete their life cycles in relatively dry environments, compared to those of non-seed-producing vascular plants.