Sterility (physiology)

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

• types of organism, such as the mule, a sterile hybrid;
• individual organisms; sterility indicates an absolute and permanent inability to produce offspring, unlike infertility, which may be temporary or indicate only a reduced level of fertility.
• specific sexual organs; for example in some flowering plants, one or more stamens may be reduced to sterile staminodes.

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.

Economic uses of sterility include

• the production of certain kinds of seedless fruit, such as seedless watermelon (though sterility is not the only available route to fruit seedlessness);
• so-called terminator technology, methods for restricting the use of genetically modified plants by causing second generation seeds to be sterile;
• the sterile insect technique, 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.