Explanation

Polyembryony is of common occurrence among the gymnosperms. This is possible because more than one archegonia are fertilized and more than one zygote are formed. These develop into embryos but only one of them succeeds in developing into a complete embryo. In the conifers, there is a cleavage polyembryony. In this case, all the four cells of the young embryo separate and develop into four embryos, but only one completely develops and others abort, $e.g.,\ Pinus.$