21.   Scientists can use newer techniques to make mutations in viruses in the laboratory to study the effects of different genes in new ways.

22.   Scientists do not yet know whether the beta receptor animates different genes than does the alpha receptor, but they have begun mapping out other provocative discrepancies.

23.   Scientists know that damage to a number of different genes can trigger cancer in humans.

24.   Slightly different genes could doom some smokers to cancer death while others, whose bodies eliminate the toxins quicker, escape it.

25.   Sullivan said the AIDS virus he and DesRosiers propose to test in cancer patients would lack four different genes, while earlier live-virus vaccines lacked only one.

26.   The benefits of sexual recombination depend on the availability of lots of different genes.

27.   The different gene combinations might determine how vulnerable people are and at what age they contract diabetes.

28.   The same diseases can be caused by different genes in various ethnic groups, according to a group studying the genetic roots of high blood pressure.

29.   The same is true of the other so-called nucleotide-repeat diseases, although the stutter is found in different genes.

30.   They had been inserting genetic fragments at random in fly DNA to study disruptions in a different gene.