What is a pollen tube?
Q: What is a pollen tube?
A: A pollen tube is a passageway that transports sperm cells from the pollen grain to the ovules at the base of the pistil in seed plants.
Q: How does fertilization occur in angiosperms?
A: In angiosperms, the pollen tube germinates from the pollen grain and grows through the stigma, style, ovary and ovules to reach the eggs. As it reaches an egg, it bursts and releases two sperm cells which leads to double fertilization. One sperm unites with the egg cell to produce an embryo while a second sperm unites with the central cell (polar nuclei) to produce endosperm.
Q: What type of organisms have flagellate sperm?
A: Flagellate sperm are found in ferns, other basal land plants, many algae and some gymnosperms.
Q: How do flagellate sperms fertilize eggs?
A: Flagellate sperms swim through a watery fluid to fertilize egg cells.
Q: What is endosperm?
A: Endosperm is produced when one of two released sperms unite with polar nuclei during double fertilization process. It contains starch, proteins and oils and serves as major source of human food such as wheat, barley, rye oats or corn.
Q: How long can a single cell grow in maize plant?
A: In maize plant, single cell can grow longer than 12 inches to traverse length of pistil.
