Identify the basic structures of sexual reproduction in flowering plants and describe their function?

The flower is the sexual reproductive part of an angiosperm. It consists of four whorls of modified leaves : sepals, petals, stamens and carpals. The stamens are the male reproductive parts which includes the sporangia that produces pollen. The carpals are the female reproductive parts and includes the sporangia that produces the egg.

Pollen Development:
A pollen grain is an immature male gametophyte.
It is produced within the sporangium of the anthers.
The diploid microspore mother cell will undergo meiosis and form 4 haploid microspores.
The microspores nuclei will undergo mitosis and produce a tube nucleus and a generative nucleus.
A thick wall forms around the spore in a specific pattern, producing the pollen grain or immature male gametophyte.
Ovule Development:

The ovule is an immature seed. It is formed within the ovary and contains the female gametophyte.
The female gametophyte is the embryo sac and forms in the following way.
The megaspore mother cell undergoes meiosis to form 4 haploid (N) megaspores.
One of the 4 will continue to develop, while the other 3 dissolve.
The remaining megaspore grows and its nucleus will undergo 3 mitotic divisions, forming 1 large cell with 8 haploid nuclei.
This will develop into the embryo sac. This sac contains a specific arrangement of these nuclei in the following order: The egg cell is located near the micropyle surrounded by 2 other cells called synergids. At the opposite end 3 antipodal cells are found. In the center of the sac will be found 2 polar nuclei.
Pollination:

Pollination is the placement of the pollen on the stigma of the carpal. This pollen transfer can be accomplished by wind, insects, built in mechanical discharge, and man. Once the pollen lands on the stigma, a series of chemical reactions takes place allowing the pollen grain to begin producing a structure called the pollen tube. As this is happening, the generative nucleus will divide and produce 2 sperm nuclei. This pollen grain with the pollen tube and 3 nuclei is considered the mature gametophyte. The pollen tube will work its way through the style of the carpal and touch the micropyle of the ovule. Here the sperm nuclei will enter the embryo sac and fertilize the egg and the two polar nuclei; hence the term double fertilization. The fertilized egg (2N) will develop into the immature seed plant, while the (3N) central cell will develop into the endosperm or food storage area of the seed.

Structure of the Mature Seed:

The seed is protected by the seed coat or testa.
The micropyle is the only opening into the seed. It is through here that the water will enter to start germination.
The seed contains stored food in the form of seed leaves (cotyledons). Some seeds contain one ( monocots) while other contain 2 ( dicots).
The embryo plant contains several areas : the area above the attachment of the cotyledons is the epicotyl. This will develop into the shoots and leaves of the developing plant. The area below the attachment is called the hypocotyl. This will develop into the roots of the plant.
Development of Fruit:

The fruit of a flower develops from the ovary. They protect the seeds and allow for their dispersal. Fruits may be classified in many ways.
Simple Fruits: These fruits develop from a single ovary. Peach, cherry, soybean.
Aggregate Fruits: These fruits develop from a single flower with many carpals. Strawberry.
Multiple Fruits: Fruit develops from a group of tightly clustered flowers. Pineapple.