In seed plants such as angiosperms and gymnosperms, the
male gametophyte is the:
ovule.
pollen grain.
seed.
sperm.
egg.
A
B
C
D
E
F
G
A
B
C
D
E
F
G
As the pollen tube grows, sperm are produced inside of it by mitosis. How many sperm are produced by this process?
1
2
4
6
8
A
B
C
D
E
F
G
Inside the ovule, a diploid cell undergoes                     to form
            haploid spores.
meiosis; 1
meiosis; 2
meiosis; 4
mitosis; 1
mitosis; 2
mitosis; 4
How many of these spores will typically survive to create the embryo sac (female gametophyte)?
1
2
3
4
The surviving cell within the ovule undergoes mitosis to form an embryo sac containing how many cells?
1
2
4
7
8
True or False:
All seven cells in the embryo sac, including the cell that forms the egg, have a single nucleus.
True
False
True or False:
The advantage of double fertilization is that energy is not wasted in producing endosperm if the egg remains unfertilized.
True
False
Pollen grains are released from the male anthers of a flower, delivering the male haploid gamete to the stigma—the sticky tip of the female reproductive structure.
The pollen grain produces a tube that extends through the stigma to the ovary. Meanwhile, a cell within the ovule undergoes meiosis, forming four haploid cells, called spores. Three of these usually degenerate.
The surviving haploid spore undergoes mitosis, forming an embryo sac that contains seven haploid cells. One cell becomes the egg, another cell—with two nuclei—will form the endosperm following fertilization by a sperm cell.
When the pollen tube reaches the ovule, two sperm are released. In a process called double fertilization, one of the two sperm fuses with the egg to form a zygote. The other sperm fuses with the two nuclei in the middle of the embryo sac to form the endosperm, which nourishes the embryo.
The zygote and the endosperm continue to develop within the ovule, forming a seed that will eventually be released and grow into a mature plant.