1a 21b

1A or 1-A may refer to:

Arts and entertainment

* 1A (comics), a comic book robot
* ''1A'' (radio program), an American radio program

Politics

*
* First Amendment (disambiguation), the first amendment of various legislation

Science and technology

* Group 1A, an obsolete designation for the group 1 elements
* AMY1A, a human gene
* Alpha-1A adrenergic receptor, a human gene
* Interferon beta-1a, a drug
* Meltwater pulse 1A, a period of rapid post-glacial sea level rise, 13,500–14,700 years ago
* Melatonin receptor 1A, a human gene
* Metallothionein 1A, a human gene
* MH-1A, a nuclear power reactor and the first floating nuclear power station
* Vasopressin receptor 1A, a major receptor type for vasopressin

Sports

* Croatian 1A Volleyball League
* 1. A SKL, the 2002–2006 name of Premier A Slovenian Basketball League

Transportation, military and space

* Adcox 1-A, an American 1929 biplane
* Astra 1A, a 1988 satellite
* Class 1-A, an American military service classification
* Little Joe 1A, a 1959 unmanned NASA launch
* Mercury-Redstone 1A, a 1969 NASA mission
* Packard 1A-1500, a 1929 piston aircraft engine
* Shin Meiwa US-1A, a Japanese anti-submarine warfare aircraft
* Sisu 1A, an American 1950s sailplane
* Türksat 1A, a Turkish satellite
* List of highways numbered 1A

See also

*
* A1 (disambiguation)
* IA (disambiguation)

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