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An endosperm is formed after the two sperm nuclei inside a pollen grain reach the interior of a female gametophyte or megagametophyte, also called the embryonic sac.One sperm nucleus fertilizes the egg cell, forming a zygote, while the other sperm nucleus usually fuses with the binucleate central cell, forming a primary endosperm cell (its nucleus is often called the triple fusion nucleus).
In Arabidopsis, actin-related proteins regulate female meiosis by modulating the expression of meiotic genes in the megaspore mother cell. [3] One of the key genes whose expression is regulated is Dmc1, a gene that plays a central role in the strand-exchange reactions of meiotic recombinational repair.
A typical embryo sac contains seven cells and eight nuclei, one of which is the egg cell. Two nuclei fuse with a sperm nucleus to form the primary endospermic nucleus which develops to form triploid endosperm, which becomes the food storage tissue in the seed.
Location of ovules inside a Helleborus foetidus flower. In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the integument, forming its outer layer, the nucellus (or remnant of the megasporangium), and the female gametophyte (formed from a haploid megaspore) in its center.
The first fertilization event produces a diploid zygote and the second fertilization event produces a triploid endosperm. The germinated pollen tube must drill its way through the nutrient-rich style and curl to the bottom of the ovary to reach an ovule. Once the pollen tube reaches an ovule, it bursts to deliver the two sperm cells.
The parts of a flower Double fertilization. Double fertilization or double fertilisation (see spelling differences) is a complex fertilization mechanism of angiosperms.This process involves the fusion of a female gametophyte or megagametophyte, also called the embryonic sac, with two male gametes (sperm).
A refined grain is defined as having undergone a process that removes the bran, germ and husk of the grain and leaves the endosperm, or starchy interior. [1] Examples of refined grains include white bread, white flour, corn grits and white rice. [2] Refined grains are milled which gives a finer texture and improved shelf life. [3]
Detailed illustration of the different parts constituting a wheat kernel. The germ of a cereal grain is the part that develops into a plant; [1] it is the seed embryo. [2] Along with bran, germ is often a by-product of the milling [3] that produces refined grain products.