In animal reproductive system Asexual reproduction (i.e., reproduction not involving the union of gametes), however, occurs only in the invertebrates, in which it is common, occurring in animals as highly evolved as the sea squirts, which are closely related to the vertebrates. Temporary gonads are common among lower animals;… Read More
apicomplexans
In apicomplexan Asexual reproduction is by binary or multiple fission (schizogony). Read More
echinoderms
In echinoderm: Asexual reproduction Asexual reproduction in echinoderms usually involves the division of the body into two or more parts (fragmentation) and the regeneration of missing body parts. Fragmentation is a common method of reproduction used by some species of asteroids, ophiuroids, and holothurians, and in some… Read More
fungi
In fungus: Asexual reproduction Typically in asexual reproduction, a single individual gives rise to a genetic duplicate of the progenitor without a genetic contribution from another individual. Perhaps the simplest method of reproduction of fungi is by fragmentation of the thallus, the body of a fungus. Some… Read More
growth and development
In biological development …in plants that reproduce by vegetative division, the breaking off of a part that can grow into another complete plant. The possibilities for debate that arise in these special cases, however, do not in any way invalidate the general usefulness of the distinctions as conventionally made in biology. Read More
major references
In animal development: Reproduction and development In asexual reproduction the new individual is derived from a blastema, a group of cells from the parent body, sometimes, as in Hydra and other coelenterates, in the form of a “bud” on the body surface. In sponges and bryozoans, the cell groups from which new… Read More
In reproduction: Reproduction of organisms Multicellular organisms also reproduce asexually and sexually; asexual, or vegetative, reproduction can take a great variety of forms. Many multicellular lower plants give off asexual spores, either aerial or motile and aquatic (zoospores), which may be uninucleate or multinucleate. In some cases the reproductive body is multicellular, as in… Read More
In sex: Sexual and nonsexual reproduction …higher plants also reproduce by nonsexual means. Bulbs bud off new bulbs from the side. Certain jellyfish, sea anemones, marine worms, and other lowly creatures bud off parts of the body during one season or another, each thereby giving rise to populations of new, though identical, individuals. At the microscopic… Read More
plants
In plant: Asexual reproduction Both homosporous and heterosporous life histories may exhibit various types of asexual reproduction (vegetative reproduction, somatic reproduction). Asexual reproduction is any reproductive process that does not involve meiosis or the union of nuclei, sex cells, or sex organs. Depending on the type of… Read More
In plant reproductive system: General features of asexual systems Asexual reproduction involves no union of cells or nuclei of cells and, therefore, no mingling of genetic traits, since the nucleus contains the genetic material (chromosomes) of the cell. Only those systems of asexual reproduction that are not really modifications of sexual reproduction are considered… Read More
population ecology
In population ecology: Effects of mode of reproduction: sexual and asexual In sexual populations, genes are recombined in each generation, and new genotypes may result. Offspring in most sexual species inherit half their genes from their mother and half from their father, and their genetic makeup is therefore different from either parent or any other… Read More
protozoans
In protozoan: Reproduction and life cycles Asexual reproduction is the most common means of replication by protozoans. The ability to undergo a sexual phase is confined to the ciliates, the apicomplexans, and restricted taxa among the flagellated and amoeboid organisms. Moreover, sexual reproduction does not always result in an immediate increase… Read More
spores
In spore Spores are agents of asexual reproduction, whereas gametes are agents of sexual reproduction. Spores are produced by bacteria, fungi, algae, and plants. Read More
