Asexual Reproduction #2

Asexual reproduction is the formation of new individuals from the cell(s) of a single parent.
It is very common in plants; less so in animals.

Asexual Reproduction in Plants

All plant organs have been used for asexual reproduction, but stems are the most common. 

Stems

In some species, stems arch over and take root at their tips, forming new plants.
The horizontal above-ground stems (called stolons) of the strawberry (shown here) produce new daughter plants at alternate nodes.
Underground stems

• rhizomes
• bulbs
• corms and
• tubers

Sexual reproduction

Sexual reproduction is a biological process by which organisms create descendants that have a combination of genetic material contributed from two (usually) different members of the species. (Self-fertilization requires only one organism.) Each of two parent organisms contributes half of the offspring's genetic makeup by creating haploid gametes. Most organisms form two different types of gametes. In these anisogamous species, the two sexes are referred to as male (producing sperm or microspores) and female (producing ova or megaspores). In isogamous species, the gametes are similar or identical in form (isogametes), but may have separable properties and then may be given other different names (see isogamy). For example, in the green alga, Chlamydomonas reinhardtii, there are so-called "plus" and "minus" gametes. A few types of organisms, such as ciliates, Paramecium aurelia, have more than two types of "sex", called syngens.[4]

Asexual reproduction

Asexual reproduction is the process by which an organism creates a genetically similar or identical copy of itself without a contribution of genetic material from another individual. Bacteria divide asexually via binary fission; viruses take control of host cells to produce more viruses; Hydras (invertebrates of the order Hydroidea) and yeasts are able to reproduce by budding. These organisms often do not possess different sexes, and they are capable of "splitting" themselves into two or more individuals. On the other hand, some of these species that are capable of reproducing asexually, like hydra, yeast (See Mating of yeasts] and jellyfish, may also reproduce sexually. 

For instance, most plants are capable of vegetative reproduction—reproduction without seeds or spores—but can also reproduce sexually. Likewise, bacteria may exchange genetic information by conjugation. Other ways of asexual reproduction include parthenogenesis, fragmentation and spore formation that involves only mitosis. Parthenogenesis (from the Greek παρθένος parthenos,

Reproduction

Reproduction is the biological process by which new "offspring" individual organisms are produced from their "parents". Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction. The known methods of reproduction are broadly grouped into two main types: sexual and asexual.

In asexual reproduction, an individual can reproduce without involvement with another individual of that species. The division of abacterial cell into two daughter cells is an example of asexual reproduction. Asexual reproduction is not, however, limited to single-celled organisms. Most plants have the ability to reproduce asexually.

Sexual reproduction typically requires the involvement of two individuals or gamates, one each from opposite type of sex.

Generative reproduction in Gymnospermae

Reproductive organ called a cone or strobilus gymnospermae.

Inside there are many anteridium male strobilus containing stem cells, pollen grains. Bermeiosis cells from each stem cells formed four winged pollen grains.

In females there is a lot arkegonium strobilus. In each arkegonium there is one institution that bermeiosis stem cells, forming four haploid cells. Three dead and one living cell as an egg. This Arkegonium arkegonium down to one space.

Pollination and Fertilization Process

Strobilus male pollen th th falls on a drop of pollination (stigma end) powders reed th th th split core tube and core nucleus spermatogen spermatogen th th th two nuclei divide th sperm fertilize an egg cell in the space of the zygote arkegonium th th th seed agencies within the new plants.

Fertilization on fertilization gymnospermae called singular, since each core sperm fertilize one eg