Seed plants have flowers. Interest in plant seeds serve as generative reproduction. In the flowers are male and female genitals. Male genitals in a flower seed plants consisting of a stamen (stamens). Has stamen anthers (anthera) that is located at the end of stalk juice (filament). In anthers with one or more space juice (puzzle) which is the formation of pollen (pollen). Pollen is called the male gamete. Genitals are female (pistil) can be composed of ovary (ovarian) stalk buds (stillus), and head Pistil (stigma). Will the fruit is on the plant seeds as the presence of ovules. Plant ovary lies at the base of flower seeds (reseptakel) and shape bubble.
In the ovule, there are eggs that are female gametes. Pistil stalk is a narrow channel to pass the pollen during fertilization process. Pistil stalk function is to support the anthers. The stigma is the top of the pistil. In general, the stigma is sticky and hairy, as the place of attachment of the pollen during pollination.

a. Formation of male and female sex cells Plant Seeds

In the space sari, microspore mother cells are diploid. Stem cells divide microspore meiosis and produces four haploid microspores cells. Each cell will divide haploid microspore mitosis and produce two nuclei, the core generative and vegetative nucleus. When the flowers mature, the space will be broken and the juice will come out and the pollen falls upon the stigma. In the ovule, the stem cells are diploid megaspore. Stem cells bermeiosis megaspore produces four haploid cells. Of the four cells, only one living being megaspore cells. Tues megaspore then undergoes mitosis three times resulting in eight haploid nuclei. Six core will evolve into six haploid cells. Furthermore, the three moved into pole cells and three other cell antipode move to the poles mikrofil. The two remaining core moves to the center of the ovule. Two of these nuclei fuse into a single diploid polar nucleus. Three cells were found in the polar antipodes cells called antipodes. Three cells were found in the polar mikrofil consists of one egg cell and two synergids.

b. Pollination in Plant Seeds

Plant seeds when the flowers mature, the space will be broken and the juice out of the pollen grains. Then, the pollen falls on the stigma. Events fall or attachment of pollen over the stigma is called pollination (pollination). Based on the origin of pollen, the pollination can be divided into three, namely self-pollination (autogami), pollination neighbor (geitonogami), and cross-pollination (allogami). Autogami occurs when the pollen and pistil of a flower are contained on a single plant. Plant rice and soybeans are examples of plants that do autogami. Geitonogami occurs when the pollen and pistil of another flower that comes from being at one plant. Geitonogami example is the corn plant. Allogami occurs when the pollen and pistil are from other similar flowers, pollination allogami examples are papaya plants and bark.

c. Fertilization on Plant Seeds

Fertilization is the process of fusion between nuclei of male and female sex cells. When the pollen has been falling over the stigma, generative nucleus will bermitosis form two generative nuclei. Generative nucleus will form a pollen tube that moves along the shaft pistil. Both generative core moves behind him. After arriving at the biological institute, one generative nucleus will fertilize the egg to form a diploid zygote. One other generative nucleus will fertilize the polar nuclei to form the core of a triploid siblings secondary institutions. Core bladder secondary institutions will develop into the endosperm tissue which is the food reserves for potential new plant. Thus, the seed plants closed, there was a so-called double fertilization double fertilization.

Leave a Reply.