- Within the ovary are egg-producing structures called ovules. Each
ovule contains one developing egg and other cells that support the egg.
22.11 Development of pollen and ovule culminate in fertilization
*diagram on page 482*
The life cycle of plants are characterized by an alternation of
generations, in which haploid(n) and diploid (2n) generations take turns
producing each other.
Haploid refers to a cell having a single set of chromosomes, while diploid
refers to cells having two sets. In your body, all your cells are diploid except
for your gametes (sperm or eggs), which are haploid.
root, stems, leaves and most of the reproductive structures are diploid. -
There are specific names for these generations: the haploid generation is
gametophyte and the diploid generation is the sporophyte. - Within the
diploid sporophyte, cells in the anther undergo meiosis. The result is
called spores. - Each spore undergoes mitosis to form gametes (a
pollen grain). This is the sperm-containing
gametophyte. (contains the tube cell, and generative cell) - Cells within the
ovule also undergo meiosis to produce spores. One of these spores
mitosis to form an embryo sac. This is the egg-containing gametophyte. -