81.   But why genes are so important remains the source of considerable scientific investigation.

82.   By noting which RNA sequences were present and which were absent, the chip created a rec-ord of which genes were on and which were off.

83.   Companies conducting gene therapy trials are therefore required to monitor where in the body the new genes are being inserted.

84.   Critics argue that genes are not inventions and should not be patented.

85.   Curiously, the MIS gene is on an ordinary chromosome, not on the Y, so both males and females have it.

86.   DNA, he says, is like an encyclopedia, in which genes are the sentences and their chemical bases the alphabet.

87.   Each gene is a paragraph in a volume.

88.   Even though human and chimp genes are very similar, those used to operate brain cells show very different patterns of activity, the study found.

89.   Even knowing which genes are responsible for cystic fibrosis, muscular dystrophy, sickle cell anemia, and many other illnesses, scientists have not come up with cures.

90.   Even though the human genome sequence has been determined, scientists still do not know the identities of many genes or even how many genes there are.