Using a long-established technique, these donor cells will then be injected into the embryo of a freshly laid, fertilized recipient egg, forming a chick that is a chimera. Strictly speaking a chimera isnt a clone, because it contains cells from both donor and recipient. But Fitzgerald says it will be enough if, say, 95 percent of a chickens body develops from donor cells. In the poultry world, it doesnt matter if its not 100 percent, he says.
Another challenge for Origen is to scale up production. To do this, it has teamed up with Embrex, which produces machines that can inject vaccines into up to 50,000 eggs an hour. Embrex is now trying to modify the machines to locate the embryo and inject the cells into precisely the right spot without killing it.
In future, Origen imagines freezing stem cells from different strains of chicken. If orders come in for a particular strain, millions of eggs could be produced in months or even weeks. At present, maintaining all the varieties the market might call for is too expensive for breeders, and it takes years to bread enough chickens to produce the billions of eggs that farmers need.
41.Which statement is the best description of the new era of factory farming according to the first paragraph?
A. Eggs are all genetically engineered.
B. Thousands of eggs are produced every hour.
C. Cloned chickens are bulk-produced with the same growth rate, weight and taste.
【2014年职称英语理工类B级阅读理解精华练习(9)】相关文章:
最新
2016-03-01
2016-03-01
2016-03-01
2016-03-01
2016-03-01
2016-03-01