How do pine trees grow?

Did you know that pine cones contain seeds from which new pine trees can grow?
Each pine tree produces some male cones and some female cones.
Cone-bearing trees or shrubs are known as conifers. 
If you have pine trees growing near your home, try to find a cone of each type.
Ask an adult to cut the cones carefully in half from top to bottom, and then you can see what's inside each one.
Both male and female cones are made up of many scales arranged round a central axis.
In the female cone the scales are thick and woody.
Each scale carries two ovules, which will become seeds.
Male cones are smaller. They have pollen sacs on their scales, in which pollen grains are produced.
The wind carries the pollen grains, and some of them land between the scales of female cones.
It then takes three years for the male cells to join with female cells and produce a seed which will grow into a new pine tree.