The fineo reproductive structure of the Pine Tree is the cone. That Pine Trees actually produced two kinds of cones on same.
This is the male cone which produces vast amounts of tiny pollen grains.
Each pollen grain is, in fact, the male gametophyte generation, reduced to two or three cells in a waxy protective coat.
This kind of pollen grain has wing like structures to help it on its journey to the female cone. Higher up the tree, we will find the female cones.
The female cone consists of the central axis surrounded by leaf like structures called Sporophylls.
Deep inside the female cone, ovules developed into the mature female gametophyte generation, bearing fertile egg cells.
Completely eliminating the need for water, the pollen grains are carried on the winds to the female cones. Once inside, the pollen is retained and when the egg cells are ready, the pollen grain generates its special tubes so that fertilization can take place.
The male gamete fuses with the female egg cell.
This union of gametes produces the embryo of the Sporophyte generation.
The embryo is protected inside the tough seed coat, which is surrounded by a papery-wing case, all inside the cone.
When the cone is approximately three years old, the scale leaves open up and the seeds are blown away by the wind.
In favorable conditions, the seed germinates and a new Pporophyte generation begins.
Since the female gametophyte generation remains attached to the parent’s Sporophyte throughout its development, there is no period in the life cycle of the pine tree that requires free water.
In fact, the pine tree exhibits many adaptations that help it conserve water.
The leaves are needle like, reducing the surface area available for lost of water.
On the outside, the needle has a thick waxy cuticle to retain moisture, while the stomata are sunken deeply below the epidermis prevent water lost.
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