The stages of a pine life cycle are linked by orange and blue solid arrows to show the relationship between them. The whole cycle is divided into two parts:

1. Fertilization - It starts with fertilization of pollen grains (N) (male gametophytes) and egg cells having discharged nucleus and pollen tube. It proceeds further with zygote, seed, germinated seed, seedling and then mature sporophyte. A mature sporophyte produces pollen cone and seed cone. A pollen cone produces pollen grains and a seed cone produces cone scale with ovules. This is the completion of first part of cycle.
2. Meiosis - It starts with meiosis of ovule and formation of female gametophyte that is egg cell. Again the cycle goes to fertilization with pollen grain and egg cells and the cycle continues.