Word: dna
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Dates: during 1990-1999
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This may be cold comfort, but when it comes to having children, nobody knows what is in store. For biological parents, kids are a roll of the DNA dice. Adoptive parents face greater risks, for their children carry a knapsack of genetic and cultural imponderables. Yet there are couples who heroically try to create a home, a family, a rich life for orphans from the U.S. and, increasingly, the Third World...
When a microbe replicates itself over many generations, mutations in the DNA that forms the organism's genetic blueprint can sometimes make it safe from an antibiotic. If, for example, the drug kills the bacterium by latching onto a specific molecule on its cell wall, a change in that molecule could make it impossible for the antibiotic to stick to its target. It's something like the protect-the-perimete r strategy used by defenders of ramparts on medieval fortresses. In other cases, says Neu, the bacteria develop enzymes capable of destroying the antibiotics and even molecular pumps that expel...
Once a bacterium has a protective combination of genes, they are duplicated every time the bacterium reproduces itself. Moreover, the microbe can pass its genetic shield to a different strain of bacteria through a process called conjugation, the bacterial equivalent of sex. In addition to exchanging DNA in the form of chromosomes, conjugating bacteria can swap smaller snippets of DNA called plasmids. Like viruses, plasmids make exceedingly effective shuttles for carrying drug-resistant traits from one bacterium to another...
...discovery, the largest velociraptor ever found was about the size of a human. But that did not stop Steven Spielberg from featuring supersize velociraptors in his upcoming movie Jurassic Park, based on the Michael Crichton novel of the same name. In it, real dinosaurs, grown from bits of ancient DNA to populate a theme park, go on a rampage and terrorize humans trapped there. Until the Utah find, Spielberg's creatures would have been just another Hollywood exaggeration; now, they will seem even more monstrously real...
...time. The forests in these wet areas are open and cool, even though the equatorial sun beats down on the upper stories of the canopy. At one point we discover leopard droppings containing black hair and some bone bits. The Pygmies claim it is gorilla hair, though only dna analysis could tell for sure. Fay thinks it's possible, since he has documented leopard attacks on gorillas. Samory, one of the trackers, claims leopards kill the immensely strong apes with surprise attacks in which the cat quickly snaps its jaws around the gorilla's throat. The Ndoki may be innocent...