Assertion: male gametophyte | /r/CapableOf | develop tube
Facets:
Source sentences:
text: A number of parts of the reproductive process are common to both angiosperms and gymnosperms: (1) they produce seeds at maturity; (2) the megasporangium, unlike that of heterosporous seedless plants, is covered by one or two cellular layers called integuments and is termed an ovule; (3) there is a minute passageway, or micropyle, through the integuments; (4) the ovule matures as a seed; (5) only one megasporocyte is present and undergoes meiosis in the megasporangium to produce four megaspores, only one of which usually is functional; (6) the megaspore is never discharged from its megasporangium and ovule; (7) one female gametophyte is produced within each megasporangium and ovule; (8) the microspores begin their development into male gametophytes while still enclosed in the microsporangia; (9) as they mature, the male gametophytes, which are contained within the microspore wall and are termed pollen grains, develop a tube that conveys sperm to the egg cell; (10) union of sperm and egg and development of an embryonic sporophyte from the zygote occur within the female gametophyte (sometimes called the “embryo sac”), which is covered by the remains of the megasporangium and by integuments; (11) as the embryo develops, the ovule matures as a seed.