Gonochorism
Encyclopedia
In biology
, gonochorism (Greek
offspring + disperse) or unisexualism describes sexually reproducing
species in which individuals have just one of at least two distinct sexes. The term is most often used with animals (whereas dioecious
is usually used with plants). The sex of an individual may change during its lifetime, this can for example be found in parrotfish
. Sex is most often genetically determined, but may be determined by other mechanisms. For example, alligator
s use temperature dependent sex determination during egg incubation. Good examples of gonochoric or dioecious pollination
are hollies
, and kiwifruit
. In these plants the male plant which supplies the pollen
is referred to as the pollenizer
. The vast majority of mammals are gonochorists.
Gonochorism stands in contrast to other reproductive strategies such as hermaphroditism
.
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
, gonochorism (Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
offspring + disperse) or unisexualism describes sexually reproducing
Sexual reproduction
Sexual reproduction is the creation of a new organism by combining the genetic material of two organisms. There are two main processes during sexual reproduction; they are: meiosis, involving the halving of the number of chromosomes; and fertilization, involving the fusion of two gametes and the...
species in which individuals have just one of at least two distinct sexes. The term is most often used with animals (whereas dioecious
Dioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...
is usually used with plants). The sex of an individual may change during its lifetime, this can for example be found in parrotfish
Parrotfish
Parrotfishes are a group of fishes that traditionally had been considered a family , but now often are considered a subfamily of the wrasses. They are found in relatively shallow tropical and subtropical oceans throughout the world, but with the largest species richness in the Indo-Pacific...
. Sex is most often genetically determined, but may be determined by other mechanisms. For example, alligator
Alligator
An alligator is a crocodilian in the genus Alligator of the family Alligatoridae. There are two extant alligator species: the American alligator and the Chinese alligator ....
s use temperature dependent sex determination during egg incubation. Good examples of gonochoric or dioecious pollination
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...
are hollies
Holly
Ilex) is a genus of 400 to 600 species of flowering plants in the family Aquifoliaceae, and the only living genus in that family. The species are evergreen and deciduous trees, shrubs, and climbers from tropics to temperate zones world wide....
, and kiwifruit
Kiwifruit
The kiwifruit, often shortened to kiwi in many parts of the world, is the edible berry of a cultivar group of the woody vine Actinidia deliciosa and hybrids between this and other species in the genus Actinidia....
. In these plants the male plant which supplies the pollen
Pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...
is referred to as the pollenizer
Pollenizer
A pollenizer or polleniser, sometimes pollinizer or polliniser is a plant that provides pollen.In American English, the words pollenizer and pollinator are often confused: A pollinator is the biotic agent that moves the pollen, such as bees, moths, bats, and birds...
. The vast majority of mammals are gonochorists.
Gonochorism stands in contrast to other reproductive strategies such as hermaphroditism
Hermaphrodite
In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...
.