1. Pollination is the transfer of pollen from an anther to the stigma in angiosperms or from the microsporangium to the micropyle in gymnosperms.

2. Fertilization is A process in sexual reproduction that involves the union of male (sperm) and female (ovum) gametes (each with a single, haploid set of chromosomes) to produce a diploid zygote.

3. Embryo is (in botany) A young, developing plant, such as the rudimentary plant inside the seed of higher plants or that inside the archegonium of mosses and ferns.

4. Ovulum is a rudimentary seed or the plant part that contains the embryo sac and hence the female germ cell, which after fertilization develops into a seed.

5. Endosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization.

6. Formation of male gametes. In the anthers of a flower, certain diploid cells undergo meiosis, forming haploid spores (called microspores). These microspores divide by mitosis to form two-celled pollen, consisting of a tube cell and a generative cell. Formation of female gametes. The female gametes, or eggs, are formed in the ovules, within the flower. A certain diploid cell undergoes meiosis; however, in this case the result is four haploid megaspores). Three of the megaspores die, and the remaining one undergoes mitosis several times. One of these daughter cells then functions as an egg, ready to be united with a sperm.

7. Embryo called as small plant because seeds are ovule (ovulum) of flowering plants that had been grown. Seeds can be protected by other organs. From an evolutionary standpoint, the seeds are tiny plant embryo or modified so that it can last longer on less suitable conditions for growth.

8. The first division of the zygote is almost always asymmetrical (uneven) and transverse to its long axis, producing a large basal (bottom) cell. The apical cell divides vertically and the basal cell divides transversely to form a 4-celled structure called proembryo (T shaped). The upper three cells of the proembryo divide further both by anticlinal and periclinal divisions to form a 32-celled globular proembryo. Development of various organs of embryo or Organogenesis occurs in the 32-celled proembryo. The outer most layer of cells of the globular proembryo develop into a dinstinct layer called dermatogen which forms the future epidermis. The inner cells of the upper region develop into the cotyledons and plunule while the ower cells develop into the radicle. The cotyledonary cells divide rapidly the plumule cells. Therefore the embryo becomes heart shaped. When thee cotyledons aree completely formed, they enclose the plumule at the base. The lower most cell formed by the basal cell does not contribute to embryo structure. It may divide by a few transverse divisions to form a filamentous structure known as the suspensor, which anchors the embryo to the embryo sac wall and helps in nutrient adsorbtion from the surrounding tissues.