Sexual Reproduction in Flowering Plants Test - 20

Double fertilization is a complex fertilization mechanism of flowering plants (angiosperms). This process involves the joining of a female gametophyte (megagametophyte, also called the embryo sac) with two male gametes (sperm). The pollen tube proceeds to release the two sperm in the megagametophyte.

Self-pollination is when pollen from the same plant arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms).

The arrangement of nuclei in a normal embryo sac in dicot plants is 3+2+3. After cell division 8 nucleii are formed, 3 of which goes upside to the chalazal end, 3 comes down to the micropyle end and 2 remain suspended in the central yolk region.

The deposition of a wall of callose begins round each microspore mother cell within the primary cell wall during early prophase of meiosis I in both Allium and Cyclamen. This occurs as a result of the breaking down of the middle lamella of adjacent microspore mother cells.

Filiform apparatus is highly thickened structure of synergids cell wall at the micropylar end, consisting of numerous finger-like projections into the synergid cytoplasm. The synergids are essential for the cessation of pollen tube growth and release of the sperm cells.

Coconut Endosperm is coconut water, the liquid endosperm of green coconuts (Cocos nucifera). It has been freeze dried to a free-flowing powder form using a patented lyophilization process which produces a stable composition retaining the inherent biological activity of its nutrients and growth factors.

Geitonogamy is the Transfer of Pollen grains from the anther to the stigma of another flower of same plant. Ex-Corn

When pollen is transported by wind, this is called anemophily. Wind-pollinated plants do not invest in resources that attract pollinating organisms, such as showy flowers, nectar, and scent. Instead, they produce larger quantities of light, dry pollen from small, plain flowers that can be carried on the wind.

The embryo sac is female gametophyte of the flowering plant. The cells of the embryo sac are arranged in following manners: Two nuclei are formed when the 'nucleus of the functional megaspores' (n) divides mitotically which results in formation of two nucleated embryo sac.

It is the tough outer wall of pollen grains and the spores of plants which is highly stable and cannot be degraded by any chemical agent.