angiosperm reproduction

Pollination in Flowering Plants : 

Pollination in Flowering Plants

Angiosperms : 

Angiosperms Angiosperm: a plant that has flowers and produces seeds enclosed within a carpel. The angiosperms are a large group and include herbaceous plants, shrubs, grasses, and most trees.

In the Anther : 

In the Anther Microsporocytes undergo meiosis to produce haploid microspores. Each of these microspores develop into the pollen grain. These pollen grains form two cells.

Pollen Grain : 

Pollen Grain The two cells of the pollen grain are, 1. generative cell: divides to form the male gametes. 2. tube cell: forms the pollen tube.

In the Ovule : 

In the Ovule Each ovule contains a megasporyte (mother cell) that undergoes meiosis to form 4 haploid megaspores - 3 disintegrate. The surviving megaspore divides mitotically to produce an embryo sac.

the Embryo Sac : 

the Embryo Sac The embryo sac is composed of 7 cells with 8 haploid nuclei. Of these 7 cells there is one egg cell and one central cell. The central cell has 2 haploid polar nuclei.

Angiosperm Reproduction : 

Angiosperm Reproduction The anther sac splits open and releases pollen grains. The pollen grain lands on the stigma and if compatible, fertilization will proceed. The tube cell begins to produce the pollen tube down the length of the style, followed by the generative cell. The generative cell divides to produce two sperm nuclei. The two new sperm cells are deposited into the embryo sac.

Double Fertilization : 

Double Fertilization The first sperm cell fuses with the egg to form a zygote. The zygote divides mitotically to produce a multicellular embryo in the seed. The second sperm cell enters the central cell and fuses with the two polar nuclei forming a triploid endosperm (3N). - The endosperm provides nourisment for the embryo.

Angiosperm Reproduction : 

Angiosperm Reproduction

Voila : 

Voila The fruit is the mature version of the ovary. The seed is the mature version of the ovule.

From Blossom to Fruit : 

From Blossom to Fruit