Each year, the tree forms new cells, arranged in concentric circles called annual rings or annual growth rings. These annual rings show the amount of wood produced during one growing season.
In North United States, the growing season begins in spring.The different stages in the growth of ring is shown in the attachment in different seasons.
The gametes are genetically identical with the parent cell and with one another. The gametes have half the chromosomes of the parent cell, and are genetically identical with one another.