Appendix C: 

 Glossary 



the gene coding for the protein. Proteins are required for the structure, function, 

 and regulation of the body's cells, tissues, and organs, and each protein has unique 

 functions. Examples are hormones, enzymes, and antibodies. 



Recombinant DNA technologies: Procedures used to join together DNA segments in a 

 cell-free system (an environment outside of a cell or organism). Under appropriate 

 conditions, a recombinant DNA molecule can enter a cell and replicate there, either 

 autonomously or after it has become integrated into a cellular chromosome. 



Resolution: Degree of molecular detail on a physical map of DNA, ranging from low 

 to high. 



Restriction enzyme, endonuclease: A protein that recognizes specific, short 

 nucleotide sequences and cuts DNA at those sites. There are over 400 such 

 enzymes in bacteria that recognize over 100 different DNA sequences. See 



restriction enzyme cutting site. 



Restriction enzyme cutting site: A specific nucleotide sequence of DNA at which a 

 particular restriction enzyme cuts the DNA. Some sites occur frequently in DNA 

 (e.g.. every several hundred base pairs), others much less frequently (e.g.. every 

 10,000 base pairs). 



RFLP, restriction fragment length polymorphism: Variation, between individuals, in 

 DNA fragment sizes cut by specific restriction enzymes; polymorphic sequences 

 that result in RFLPs are used as markers on both physical maps and genetic 

 linkage maps. RFLPs are usually caused by mutation at a cutting site. See 

 marker. 



Ribosomal RNA, rRNA: A class of RNA found in the ribosomes of cells. 



RNA, ribonucleic acid: A chemical found in the nucleus and cytoplasm of cells; it 



plays an important role in protein synthesis and other chemical activities of the cell. 

 The structure of RNA is similar to that of DNA. There are several classes of RNA 

 molecules, including messenger RNA, transfer RNA, ribosomal RNA, and other 

 small RNAs, each serving a different purpose. 



Sequence: The order of the nucleotides in a nucleic acid or order of amino acids in a 

 protein. 



Sequence-tagged sites (STSs): Short (200-500 base pairs) DNA sequences that have a 

 single occurrence in the human genome and whose location and ba.se sequence are 

 known. Detectable by polymerase chain reaction, STSs are useful for localizing 

 and orienting the mapping and sequence data reported from many different 

 laboratories and could serve as landmarks on the developing physical map of the 

 human genome. 



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