: These are unique because their mature pollen tubes do not carry the sperm all the way to the egg. Instead, the tube functions as an anchor and nutrient-absorber, eventually bursting to release large, swimming sperm.
: The active transport of nutrients and the vegetative nucleus toward the growing front. mature orgasm tubes
: After a pollen grain lands on a compatible receptive surface (the stigma in flowering plants or the micropyle in gymnosperms), it germinates. A tube emerges and grows through the maternal tissue. : These are unique because their mature pollen