Polyploid in the context of "Xenopus"

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). It begins when a pollen grain adheres to the stigmatic surface of the carpel, the female reproductive structure of angiosperm flowers. The pollen grain begins to germinate (unless a type of self-incompatibility that acts in the stigma occurs in that particular species and is activated), forming a pollen tube that penetrates and extends down through the style toward the ovary as it follows chemical signals released by the egg. The tip of the pollen tube then enters the ovary by penetrating the micropyle opening in the ovule, and releases two sperm into the embryonic sac (megagametophyte).

The mature embryonic sac of an unfertilized ovule is 7-cellular and 8-nucleate. It is arranged in the form of 3+1+3 (from top to bottom) i.e. 3 antipodal cells, 1 central cell (binucleate), 2 synergids & 1 egg cell. One sperm fertilizes the egg cell and the other sperm fuses with the two polar nuclei of the large central cell of the megagametophyte. The haploid sperm and haploid egg fuse to form a diploid zygote, the process being called syngamy, while the other sperm and the diploid central cell fuse to form a triploid primary endosperm cell (triple fusion). Some plants may form polyploid nuclei. The large cell of the gametophyte will then develop into the endosperm, a nutrient-rich tissue which nourishes the developing embryo. The ovary, surrounding the ovules, develops into the fruit, which protects the seeds and may function to disperse them.

A xenoma (also known as a 'xenoparasitic complex') is a growth caused by various protists and fungi, most notably microsporidia. It can occur on numerous organisms; however is predominantly found on fish.

In most cases the host cell and nuclei suffers from hypertrophy resulting in a change in organisation of the cell and its structure and can result in polyploid nuclei. This outcome is due to the microsporidian parasite proliferating inside the host cell. This results in a 'symbiotic co-existence' between the parasite and the host cell. This forms the xenoparasitic complex. They tend to contain numerous cellular components as well as microsporidia at different developmental stages and spores.

In genetics, a locus (pl.: loci) is a specific, fixed position on a chromosome where a particular gene or genetic marker is located. Each chromosome carries many genes, with each gene occupying a different position or locus; in humans, the total number of protein-coding genes in a complete haploid set of 23 chromosomes is estimated at 19,000–20,000.

Genes may possess multiple variants known as alleles, and an allele may also be said to reside at a particular locus. Diploid and polyploid cells whose chromosomes have the same allele at a given locus are called homozygous with respect to that locus, while those that have different alleles at a given locus are called heterozygous. The ordered list of loci known for a particular genome is called a gene map. Gene mapping is the process of determining the specific locus or loci responsible for producing a particular phenotype or biological trait. Association mapping, also known as "linkage disequilibrium mapping", is a method of mapping quantitative trait loci (QTLs) that takes advantage of historic linkage disequilibrium to link phenotypes (observable characteristics) to genotypes (the genetic constitution of organisms), uncovering genetic associations.

The following is a list of banana cultivars and the groups into which they are classified. Almost all modern cultivated varieties (cultivars) of edible bananas and plantains are hybrids and polyploids of two wild, seeded banana species, Musa acuminata and Musa balbisiana. Cultivated bananas are almost always seedless (parthenocarpic) and hence sterile, so they are propagated vegetatively (cloned). They are classified into groups according to a genome-based system introduced by Ernest Cheesman, Norman Simmonds, and Ken Shepherd, which indicates the degree of genetic inheritance from the two wild parents and the number of chromosomes (ploidy). Cultivars derived from Musa acuminata are more likely to be used as dessert bananas, while those derived from Musa balbisiana and hybrids of the two are usually plantains or cooking bananas.

Musa × paradisiaca is a species as well as a cultivar, originating as the hybrid between Musa acuminata and Musa balbisiana, cultivated and domesticated by humans very early. Most cultivated bananas and plantains are polyploid cultivars either of this hybrid or of M. acuminata alone. Linnaeus originally used the name M. paradisiaca only for plantains or cooking bananas, but the modern usage includes hybrid cultivars used both for cooking and as dessert bananas. Linnaeus's name for dessert bananas, Musa sapientum, is thus a synonym of Musa × paradisiaca.

Oryzalin is a herbicide of the dinitroaniline class. It acts through the disruption (depolymerization) of microtubules, thus blocking anisotropic growth of plant cells. It can also be used to induce polyploidy in plants as an alternative to colchicine.

Oryzalin's mode of action is inhibition of microtubule assembly, so its HRAC classification is Group D (Australia), Group K1 (global) or Group 3 (numeric).

Somatic fusion, also called protoplast fusion, is a type of genetic modification in plants by which two distinct species of plants are fused together to form a new hybrid plant with the characteristics of both, a somatic hybrid. Hybrids have been produced either between different varieties of the same species (e.g. between non-flowering potato plants and flowering potato plants) or between two different species (e.g. between wheat Triticum and rye Secale to produce Triticale).

Uses of somatic fusion include developing plants resistant to disease, such as making potato plants resistant to potato leaf roll disease. Through somatic fusion, the crop potato plant Solanum tuberosum – the yield of which is severely reduced by a viral disease transmitted on by the aphid vector – is fused with the wild, non-tuber-bearing potato Solanum brevidens, which is resistant to the disease. The resulting hybrid has the chromosomes of both plants and is thus similar to polyploid plants.Somatic hybridization was first introduced by Carlson et al. in Nicotiana glauca.