See polymerase chain reaction. The outward physical characteristics of an organism. A molecule made up of a stri ng of amino acids. A protein is an example of a polypeptide. The active molecules in all cells.
Proteins control biochemical reactions and determine the physical structure of organisms.
A gene which must b e present on both chromosomes in a pair to show outward signs of a certain characteristic. A form of DNA produced by splicing together segments of DNA from two or more organisms. A protein that recognizes specific, short sequences of DNA and cuts at those sites. See also Restriction enzyme cutting site . A class of RNA found in the ribosomes of cells.