Gametophyte distinct egg-producing and sperm-producing gametophytes, but these gametophytes develop from the same kind of spore inside the same sporangium; "Sphaerocarpos" is an example of such a plant. In the seed plants, the microgametophyte is called pollen. Seed plant microgametophytes consists of two or three cells when the pollen grains exit the sporangium. The megagametophyte develops within the megaspore of extant seedless vascular plants and within the megasporangium in a cone or flower in seed plants. In seed plants, the microgametophyte (pollen grain) travels to the vicinity of the egg cell (carried by a physical or animal vector), and produces two
Water-based pipe coating Water-based pipe coating A water-based pipe coating is an environmentally friendly coating that is applied to the inner and outer surfaces of ductile iron pipe. The coating serves to protect the water supply lines from corrosion whether from the outside or the inside. It also serves to protect the drinking water from contamination. The coating is an emulsion manufactured using asphaltene and water primarily, with other raw materials according to the manufacturer’s specifications. Water-based coatings began development in the late 1980s. In the early 1990s they began to be widely used, specifically marketed towards drinking water supply lines. Previously, water