a

Noun

• the blood group whose red cells carry the A antigen

• the 1st letter of the Roman alphabet

• the basic unit of electric current adopted under the Systeme International d'Unites
  • a typical household circuit carries 15 to 50 amps
    

• (biochemistry) purine base found in DNA and RNA; pairs with thymine in DNA and with uracil in RNA

• one of the four nucleotides used in building DNA; all four nucleotides have a common phosphate group and a sugar (ribose)

• any of several fat-soluble vitamins essential for normal vision; prevents night blindness or inflammation or dryness of the eyes

• a metric unit of length equal to one ten billionth of a meter (or 0.0001 micron); used to specify wavelengths of electromagnetic radiation

Related words

• Synonyms: 
  A , type A , group A , ampere , amp , adenine , deoxyadenosine monophosphate , vitamin A , antiophthalmic factor , axerophthol , angstrom , angstrom unit