(Solved): Examine a cluster of microsporangiate strobili, or "male cones," and note their position and arrang ...

Examine a cluster of microsporangiate strobili, or "male cones," and note their position and arrangement on the stem (manual Figure 17-1a). Examine one of the male cones under a dissecting microscope. Note that the microsporophylls are arranged helically along the axis of the cone. Remove a microsporophyll and examine it. Each microsporophyll bears two microsporangia, or pollen sacs, in which microspore mother cells (microsporocytes) are formed. Each microspore mother cell eventually undergoes meiosis to give rise to four microspores, which develop into the pollen grains, or immature male gametophytes (microgametophytes). Although commonly referred to as male cones, this designation for the microsporangiate strobili is not accurate.