14
C a radioactive isotope of normal carbon (12C) emitting a weak beta particle. The half-life of 14C is 5,700 years. This radioisotope is extensively used as a tracer in molecular biology.
A, B antigens
Mucopolysaccharides responsible for the ABO blood group system. The A and B antigens reside on the surface of erythrocytes, and differ only in the sugar attached to the penultimate monosaccharide ...
Aapa mires
Fens, sometimes called ‘string bogs’, of circumpolar distribution, found in northern Scandinavia and boreal Canada. They are soligenous mires with ridges arranged roughly normal to the slope, along ...
abacá
(Manila hemp)The strongest of the hard, natural fibres. It is extracted from the pseudostems of Musa textilis (see MUSA), a relative of the edible bananas. Grown mainly in the Philippines, and native ...
abaptation
The process by which an organism is fitted to its environment as a consequence of the characters it inherits, which have been filtered by natural selection in previous environments. Because present ...
abaxial
Of a plant organ, facing away from the axis or main stem (e.g. the lower surface of leaves). Compare adaxial.
