"The pore in the integuments of an angiosperm ovule through which sperm is delivered is the micropyle. Of the two sperm that are discharged through the micropyle, one sperm fertilizes the egg, forming a diploid zygote. The other sperm fuses with the two nuclei in the large central cell of the female gametophyte, producing a triploid cell that will develop into endosperm to nourish the developing embryo.
a) The pollen tube is the structure produced from the pollen grain to deliver the sperm through the micropyle.
b) The stigma is the sticky tip of a flower's carpel that receives pollen.
c) The embryo sac is another name for the female gametophyte within the ovule.
d) The sepals are the modified leaves at the base of a flower that enclose the flower before it opens."
