Pollen tube tubes. The presence of multiple grains of pollen has been observed to stimulate quicker pollen tube growth in some plants. The vegetative cell then produces the pollen tube, a tubular protrusion from the pollen grain, which carries the sperm cells within its cytoplasm. The sperm cells are the male gametes that will join with the egg cell and the central cell in double fertilization. The germinated pollen tube must then drill its way through the nutrient-rich style and curl to the bottom of the ovary to reach the ovule. Once the pollen tube reaches an ovule, it bursts to deliver
Chemical Agent Resistant Coating Chemical Agent Resistant Coating Chemical Agent Resistant Coating is a paint commonly applied to military vehicles to provide protection against chemical and biological weapons. The surface of the paint is engineered to be easily decontaminated after exposure to chemical warfare and biological warfare agents. The paint is also resistant to damage and removal by decontaminating solutions. Two-component systems (e.g. epoxy or polyester-based) are often employed. This coating is described in MIL-DTL-53072E. As of 2018, the U.S. Army Research Laboratory (ARL) led research and development activity for CARC and was the approving authority of CARC products for the Department of Defense