Sterility (physiology)
Encyclopedia
Sterility is the physiological inability to effect sexual reproduction
in a living thing, members of whose kind have been produced sexually. The term may be used in reference to
Sterility has a wide range of causes. It may be an inherited trait, as in the mule; or it may be acquired from the environment, for example through physical injury or disease, or by exposure to radiation
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Economic uses of sterility include
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...
in a living thing, members of whose kind have been produced sexually. The term may be used in reference to
- types of organism, such as the muleMuleA mule is the offspring of a male donkey and a female horse. Horses and donkeys are different species, with different numbers of chromosomes. Of the two F1 hybrids between these two species, a mule is easier to obtain than a hinny...
, a sterile hybrid; - individual organisms; sterility indicates an absolute and permanent inability to produce offspring, unlike infertilityInfertilityInfertility primarily refers to the biological inability of a person to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term...
, which may be temporary or indicate only a reduced level of fertility. - specific sexual organs; for example in some flowering plants one of more stamenStamenThe stamen is the pollen producing reproductive organ of a flower...
s may be reduced to sterile staminodeStaminodeIn botany, a staminode is an often rudimentary, sterile or abortive stamen. This means that it does not produce pollen. Staminodes are frequently inconspicuous and stamen-like, usually occurring at the inner whorl of the flower, but are also sometimes long enough to protrude from the...
s.
Sterility has a wide range of causes. It may be an inherited trait, as in the mule; or it may be acquired from the environment, for example through physical injury or disease, or by exposure to radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
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Economic uses of sterility include
- the production of certain kinds of seedless fruitSeedless fruitA seedless fruit is a fruit developed to possess no mature seeds. As consumption of seedless fruits is generally easier and more convenient, they are considered commercially valuable....
, such as seedless watermelon (though sterility is not the only available route to fruit seedlessness); - so-called terminator technologyTerminator TechnologyGenetic use restriction technology , colloquially known as terminator technology, is the name given to proposed methods for restricting the use of genetically modified plants by causing second generation seeds to be sterile...
, methods for restricting the use of genetically modified plants by causing second generation seeds to be sterile; - the sterile insect techniqueSterile insect techniqueThe sterile insect technique is a method of biological control, whereby overwhelming numbers of sterile insects are released. The released insects are normally male as it is the female that causes the damage, usually by laying eggs in the crop, or, in the case of mosquitoes, taking a bloodmeal from...
, a method of biological control in which large numbers of sterile insects are released, which compete with fertile insects for food and mates, thus reducing the population size of subsequent generations.