<P> Once a pollen grain settles on a compatible pistil , it may germinate in response to a sugary fluid secreted by the mature stigma of certain plants . Lipids at the surface of the stigma may also stimulate pollen tube growth for compatible pollen . Plants that are self - sterile often inhibit the pollen grains from their own flowers from growing pollen 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 . </P>
<P> Once a pollen grain settles on a compatible pistil , it may germinate in response to a sugary fluid secreted by the mature stigma of certain plants . Lipids at the surface of the stigma may also stimulate pollen tube growth for compatible pollen . Plants that are self - sterile often inhibit the pollen grains from their own flowers from growing pollen 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 . </P>
when you combine an egg with the material in pollen you get
when you combine an egg with the material in pollen you get
double fertilization
double fertilization